does a hexagon have parallel sides

A regular hexagon has 6 lines of symmetry.... How Many Parallel Sides Does A Pentagon Have? a shape with five angles and five sides. Each interior angle measures 72 degrees... How Many Sides Does A Regular Pentagon Have, And What Do We Know About Its Sides And Angles? Other common names for the hex screwdriver include Allen wrench, hexagon, hex key, and security hex version. A pentagon has no parallel sides :)... How Many Right Angles Does A Regular Hexagon Have? Equilateral only means “equal sides”. How many sides does the polygon have? Hex is a Greek prefix which means 'six.'. Diagonals of 3D Shapes. How many pairs of parallel lines does a trapezoid have? The interior angles of a hexagon add up to 720 degrees. Hexagon. A regular hexagon is similar to a convex hexagon. PCBN inserts for turning cast iron and hardened steel: pcbn is the second hardest material in the world, and cbn related high precision cutting tools are introduced to industry, achieved high productivity and cost reductions. Don’t worry if you don’t have a compass and you need to draw a hexagon, since you can draw one with a ruler and a pencil. Values below 0 or above 1 are disadvised. The altitude (or height) of a trapezoid is the perpendicular distance between the two bases. Because a hexagon has an even number of sides, in a regular hexagon, opposite sides are parallel. What is the size of one of the angles? pentagon. perpendicular. How many pairs of parallel lines does a square have? (Choose 2) A. It can be either regular (with 6 equal side lengths and equal angles) or irregular (with 6 unequal side lengths and angles). The altitude (or height) of a trapezoid is the perpendicular distance between the two bases. To get rich, Getting lazy, and Being happy B. The figure below shows a few different types of trapezoids. Pattern Blocks. A hexagon has nine diagonals as shown in the following figure. To get rich, Getting lazy, and Being happy B. This is the distance between the two parallel sides. Does a hexagon have perpendicular lines? Parallel Base Age 11 to 14 Short Challenge Level. Recall that the bases are the two parallel sides of the trapezoid. badminton court petaling jaya camden catholic vs camden high basketball what shape has 6 sides and 6 vertices 1 and 2 are the parallel sides, but it doesn't matter which is which. 4. Expert answered|Score 1|jerry06|Points 83879| User: The Main Street Cinema holds 1,356 people. To prove this to yourself, draw a rectangle of 8 x 11 sitting on its bigger side (so the side of 11 units is horizontal). HEXA = 6! five 5. By singers with perfect pitch - In. zero 9. 11 What is a quadrilateral with parallel sides? A hexagon can have 0 1 2 or 3 pairs of parallel sides. A hexagon can have 0 1 2 or 3 pairs of parallel sides. A hexagon is a. A hexagon can have 0 2 3 4 5 or 6 parallel sides. A regular hexagon has 3 pairs of parallel sides. Worksheet Sides And Vertices Count And Write How Many Sides And Vertices Each 2 Dimesion Kids Math Worksheets Shapes ... math. hexagon. The length of the sides can vary even within the same hexagon, except when it comes to the regular hexagon, in which all sides must have equal length. m n . What is the area of the hexagon? Just … ... Parallelogram: A quadrilateral with two sets of opposite sides that are parallel. any shape with an odd number of equal sides has 0 parallel sides, no matter how many sides it has. The length of each side is equal to the radius (r). how many sides does a megagon haveinflation rate in vietnam 2020 how many sides does a megagon have10th result 2011 state board A trapezoid is half a parallelogram with area ( 1+ 2)ℎ 13. their internal angles are less than 180° Regular hexagon opposite side is always parallel to each other. hexagon 6. In the figure below are 3 different types of hexagons. Trapezoid. hexagon 10. The ratio of the areas of each pair of adjacent triangles is the same as that between the lengths of the parallel sides. Parallel Base Age 11 to 14 Short Challenge Level. two 8. Is this shape a regular polygon? A rectangle has 4 sides and 4 angles. How many pairs of parallel lines does a square have? A rectangle is a quadrilateral where all its internal angles are right angles. This means the octagon has eight vertices and edges. A triangle is half a parallelogram with area ℎ. The mirror has 5 sides. A rectangle has two pairs of opposite sides parallel, and four right angles. Screw in two screw eye hooks, adjusting so that the eyes are parallel. 12. Does a hexagon have 4 sides? This is a slightly unusual type of screwdriver that has become increasingly popular in recent years. zero 9. This fact is true for all hexagons since it is their defining feature. Each side is parallel to the side that is opposite to it. What polygon has 6 sides and 6 angles? As you drag any vertex, you will see that the trapezoid redraws itself keeping the height and bases constant. Some define a trapezoid as a quadrilateral having only one pair of parallel sides (the exclusive definition), thereby excluding parallelograms. m n . a shape with five angles and five sides. The length of all six sides is equal in a regular hexagon. Heptagon Angles. Next we have alternate interior angles.Located between the two intersected lines, these angles are on opposite sides of the transversal. November 2, 2021. aran woolen mills poncho. Name four types of quadrilaterals. What polygon has 6 sides and 6 angles? Calculate the perimeter of the polygon to the nearest tenth if the polygon has 6 sides. 12. Area and Perimeter of a Hexagon . philip glass - metamorphosis pdf; how many sides does a megagon havephp button link w3schools. The distances between the parallel sides are 237, 195, and 192, as shown. Regular or Irregular When all angles are equal and all sides are equal it is regular, otherwise it is irregular: Concave or Convex Yes, see explanation Explanation: As seen in this picture, A regular hexagon does have parallel lines, 3 in the case of a regular hexagon, this is because it has an even amount of sides and all internal angles are equal. Does a rectangle have 2 equal sides? ‘ A regular hexagon has six sides that are all congruent, or equal in measurement. Explanation: As seen in this picture, A regular hexagon does have parallel lines, 3 in the case of a regular hexagon, this is because it has an even amount of sides and all internal angles are equal. What is the shape of the mirror? A. triangle B. trapezoid** C. square D. hexagon 2. A hexagon is an example of a polygon, or a shape with many sides. Margins above 0 will create gaps between adjacent hexagons and serve only a visual purpose, as the data points within the margin still contribute to the hexagon's data. Screw in two screw eye hooks, adjusting so that the eyes are parallel. Let E be the intersection of the diagonals, and let F be on side DA and G be on side BC such that FEG is parallel to AB and CD. Does a trapezoid have parallel sides? The red letters indicate the sets of … hexagon 10. Face the music, Dancing in the rain, and Show your stuff C. Being happy, Being sad, and Being depressed D. Telling a story, Being informed, and The end A regular hexagon, which means a hexagon with equal sides and equal interior angles, is the shape that has 3 pairs of parallel sides. On this page, we will provide you with all the information on Octogon meaning, definition, shapes, sides, formula etc., How many pairs of parallel lines does a triangle have? Perhaps the most recognizable hexagon-shaped item in life is a common piece of hardware known as a nut. None. Add the lengths of all sides of a hexagon to find its perimeter. Does a hexagon have to have parallel sides? 6. The interior angle of the hexagon is supplementary to ∠1 because they form a linear pair, so the measure of one interior angle of the hexagon is 180 – m∠1, or 120°. They appear like a small, six-sided metal shank in an L-shape and no head. how many sides does a megagon havebenefits of donating to food banks. how many sides does a megagon have | February 14, 2022 | emergency dentist fort worth | princess cruises customer service number February 14, 2022 | emergency dentist fort worth | princess cruises customer service number =90 I2 14. How many pairs of parallel lines does a trapezoid have? A hexagon has six sides and six vertices, or points. It is also a rectangle and a parallelogram. How many sides does a hexagon have? An embolic stroke may occur if a small blood clot travels within the circle of Willis to lodge in an artery that supplies the brain. 6 What’s the opposite sides are parallel? A regular polygon with number of sides N has N lines of symmetry. There are 720 degrees in a regular hexagon (6-2)*180. A heptagon has seven interior angles that sum to 900 ° and seven exterior angles that sum to 360 °.This is true for both regular and irregular heptagons. Which of the following options show parallel construction? Recall that the bases are the two parallel sides of the trapezoid. Perhaps the most recognizable hexagon-shaped item in life is a common piece of hardware known as a nut. o A regular hexagon inscribed in a circle Triangles Classifying Triangles by Sides Classifying Triangles by Angles Triangle Sum Theorem Exterior Angle Theorem Pythagorean Theorem Angle and Sides Relationships ... Line m is parallel to line n. Parallel lines have the same slope. … Geometry. o A regular hexagon inscribed in a circle Triangles Classifying Triangles by Sides Classifying Triangles by Angles Triangle Sum Theorem Exterior Angle Theorem Pythagorean Theorem Angle and Sides Relationships ... Line m is parallel to line n. Parallel lines have the same slope. Which shape has no line of symmetry? Draw a 6” straight line on the hexagon. In most cases, the hex key driver lacks a tip or a handle. A hexagon is a shape that is commonly seen in everyday life. Which of the following options show parallel construction? zero 9. This is a slightly unusual type of screwdriver that has become increasingly popular in recent years. A regular dodecagon (12 sides) will have six pairs of parallel sides, but a regular tridecagon (13 sides) will have no parallel sides. How many sides does a pentagon have? Use the conditional statement to answer the question. Let the trapezoid have vertices A, B, C, and D in sequence and have parallel sides AB and DC. The measure of each interior angle of a regular polygon with n sides is [(n - 2)180 / n] degrees. PCBN inserts for turning cast iron and hardened steel: pcbn is the second hardest material in the world, and cbn related high precision cutting tools are introduced to industry, achieved high productivity and cost reductions. A hexagon is a closed two-dimensional figure with six sides and six corners. Area = 1/2 (b 1 + b 2) x h; 15. of 16. The mirror has 5 sides. A regular hexagon regular means all sides are the same length and all the angles are equal has three sets of parallel lines. A regular hexagon has 3 parallel sides. The radial margin of each hexagon. 72 J2 (remember that a square is a rhombus) 11. 10. So, a hexagon has more sides. Weekly Problem 46 - 2015 ... A regular pentagon together with three sides of a regular hexagon form a cradle. Which has more sides: a hexagon or a pentagon? 9. a regular octagon has 4 pairs of parallel sides. Practice Problems on Geometric Algorithms Recent Articles on Geometric Algorithms. They appear like a small, six-sided metal shank in an L-shape and no head. A hexagon has three pairs of parallel sides. An embolic stroke may occur if a small blood clot travels within the circle of Willis to lodge in an artery that supplies the brain. Hexagon (6-gon) You can switch it between a regular and irregular hexagon using the “regular” checkbox. The margin is specified in terms of fraction of the hexagon's surface diameter. ; A hemorrhagic stroke can occur if one of the blood vessels bleeds, leaking blood and compromising the blood … How many pairs of parallel lines does a square have? Geometry. A hexagon can also have 2 sets of 3 parallel sides. The converse is also true: the Braikenridge–Maclaurin theorem states that if the three intersection points of the three pairs of lines through opposite sides of a hexagon lie on a line, then the six vertices of the hexagon lie on a conic, which may be degenerate as in Pappus's hexagon theorem. How many parallel sides does a hexagon have? Each side is parallel to the side that is opposite to it. Some real-life examples of the hexagon shape are a hexagonal floor tile, pencil cross-section, clock, a honeycomb, etc. A hexagon has nine diagonals as shown in the following figure. Weekly Problem 46 - 2015 ... A regular pentagon together with three sides of a regular hexagon form a cradle. Funky Hexagon Age 11 to 14 Short Challenge Level. If it is a regular hexagon, all the sides and angles are equal. Geometry. ... a quadrilateral whose opposite sides are parallel and equal. A. Hexagon B. Pentagon C. Square D. Heptagon Weegy: Josie bought a new mirror. pentagon. The idea behind it is to put inputs and outputs at the edges of your design.In doing so, you isolate the central logic (the core) of your application from outside concerns.Having inputs and outputs at the edge means you can swap out their handlers without changing the core code. intersecting. Just … one 7. A square has two pairs of parallel sides, four right angles, and all four sides are equal. 8. Area = 1/2 (b 1 + b 2) x h; 15. of 16. ; A thrombotic stroke may occur if one of these branches becomes blocked due to disease and narrowing within the artery itself. Hexagons have two diagonals: long diagonal and short diagonal. In other words each of the six lines. It can be either regular (with 6 equal side lengths and equal angles) or irregular (with 6 unequal side lengths and angles). A pentagon has no lines parallel. one 7. Triangles. In the applet above, click on "freeze dimensions". Trapezoid. Pre-drill a hole at each end of this line. a six-sided polygon. 2. Hexagon: 6 Sides. A Pentagon has 5 sides. Honeycomb has hexagons too! A hexagon is a polygon with 6 sides and 6 angles, (hexa- means six). one 7. Hexagon: A six-sided and six-angled polygon. As you drag any vertex, you will see that the trapezoid redraws itself keeping the height and bases constant. 8. Does a hexagon have perpendicular sides? A regular octagon is a shape that has 4 pairs of parallel sides. Start by drawing a dot for the middle of your hexagon. All sides are congruent B. Pairs of sides are parallel** C. All angles are congruent** D. Geometry A. A hexagon is an example of a polygon, or a shape with many sides. How many pairs of parallel lines does a triangle have? What is the shape of the mirror? The radial margin of each hexagon. Your hexagon could be a Parallelogon with equal sides; it is not a regular hexagon unless all the angles are also equal. The most common hexagon is the regular hexagon, in which all of the sides are the same length. In a regular heptagon, each interior angle is roughly 128.57 °.. Below is the formula to find the measure of any interior angle of a regular polygon (n = number of sides): Parabola: An open curve whose points are equidistant from a fixed point called the focus and a fixed straight line called the directrix. Hexagon: A six-sided and six-angled polygon. 9. 4.2/5 (1,590 Views . Perimeter is a one dimensional measurement. Funky Hexagon Age 11 to 14 Short Challenge Level. Margins above 0 will create gaps between adjacent hexagons and serve only a visual purpose, as the data points within the margin still contribute to the hexagon's data. A six-sided polygon with equal sides is a regular hexagon. It is also a parallelogram, since it has two pairs of parallel sides. 8 What shapes have no parallel sides? A trapezoid is a quadrilateral with one pair of parallel sides. The length of each side is equal to the radius (r). ... Parallelogram: A quadrilateral with two sets of opposite sides that are parallel. =90 I2 14. 42 Votes) A rectangle has two pairs of opposite sides parallel, and four right angles. Regular Hexagon Area = 23.38 © 2020 MathsIsFun.com v0.896 Soap bubbles tend to form hexagons when they join up. Which has more sides, a pentagon or a hexagon? math. A parallelogram features three pairs of parallel sides. Then, draw a faint line of the same length above and … A hexagon is a 6-sided polygon (a flat shape with straight sides). How many pairs of parallel lines does a trapezoid have? pcbn is the short name of polycrystalline cubic boron nitride, and pcbn inserts are mainly for the hard metal turning to replace the conventional machining way … Circles of latitude are often called parallels because they are parallel to each other; that is, planes that contain any of these circles never intersect each other. But when I try it this way, it does work (the folded part sits perfectly on top, all edges matching): So this is a Line of Symmetry. 3. Area and Perimeter of a Hexagon . For example, when we answer part (D), we know that the statement: “All hexagons have three pairs of parallel sides” is not true, since we can find a counter-example (the second diagram in the solution). No. D) hexagons have three pairs of parallel sides. hexagon 6. In most cases, the hex key driver lacks a tip or a handle. Heptagon Angles. A Triangle can have 3, or 1 or no lines of symmetry: Does a hexagon have parallel lines? The interior angles of a hexagon add up to 720 degrees. 1 and 2 are the parallel sides, but it doesn't matter which is which. A hexagon has 6 sides, so it has 3 parallel sides. Center the line in the middle of the hexagonal top. 7 What does parallel sides look like? 2 See answers Advertisement Advertisement dragonmia305 dragonmia305 Answers 1 pair ... he fourth days and so on until she does at least 50 sit-ups … perpendicular. ... What is the greatest number of sides the polygon could have? two 8. So this is not a Line of Symmetry. 5. A Regular Hexagon (6 sides) has 6 Lines of Symmetry A Regular Heptagon (7 sides) has 7 Lines of Symmetry A Regular Octagon (8 sides) has 8 Lines of Symmetry How many parallel lines does a rhombus have? (Choose 2) A. Without further restrictions it might look like this: Hexagon is a two-dimensional geometrical shape that is made of six sides, having the same or different dimensions of length. How many pairs of parallel lines does a trapezoid have? Angles 2 … Values below 0 or above 1 are disadvised. 10 What has exactly one pair of parallel sides? Diagonal of a Hexagon. True or false? Which has more sides: a hexagon or a pentagon? The sum of the interior angles must be 720 degrees. PENTA = 5! A. Modeled off of the original pattern blocks developed in the 1960s, our virtual pattern blocks include a yellow hexagon, red trapezoid, orange square, blue rhombus, beige narrow rhombus, and green equilateral triangle, offering a helpful complement to the concrete manipulatives found in classrooms. Let the trapezoid have vertices A, B, C, and D in sequence and have parallel sides AB and DC. The converse is also true: the Braikenridge–Maclaurin theorem states that if the three intersection points of the three pairs of lines through opposite sides of a hexagon lie on a line, then the six vertices of the hexagon lie on a conic, which may be degenerate as in Pappus's hexagon theorem. 72 J2 (remember that a square is a rhombus) 11. If a rectangle is a square, then it has four congruent sides. A regular polygon is inscribed in a circle of radius 9 cm. Beranda. Math. Let E be the intersection of the diagonals, and let F be on side DA and G be on side BC such that FEG is parallel to AB and CD. Hexagonal architecture is a model or pattern for designing software applications.. Expert answered|Score 1|jerry06|Points 83879| User: The Main Street Cinema holds 1,356 people. Since it's a regular hexagon (six-sided polygon), we know it's made up of sets of parallel lines. In a regular heptagon, each interior angle is roughly 128.57 °.. Below is the formula to find the measure of any interior angle of a regular polygon (n = number of sides): It is the sum of the length of the sides. How many sides does a pentagon have? A hexagon has six equal sides, and opposite sides are parallel. The shape of the mirror is PENTAGON. A regular polygon is inscribed in a circle of radius 9 cm. Do hexagons have parallel sides Yes or no? Hexagonal architecture is a model or pattern for designing software applications.. Usually it is sufficient to provide a counter-example to disprove a statement. The mirror has 5 sides. The shape of the mirror is PENTAGON. The Greek prefix ‘hexa-‘ means ‘six’, and ‘ … For example, a regular hexagon has three pairs of parallel sides. Above answer is correct but only if they are regular hexagon and pentagons. Does all hexagon have 3 pairs of parallel sides? The red letters indicate the sets of parallel lines. PENTA = 5! The idea behind it is to put inputs and outputs at the edges of your design.In doing so, you isolate the central logic (the core) of your application from outside concerns.Having inputs and outputs at the edge means you can swap out their handlers without changing the core code. In the... See full … The Lemoine hexagon is a cyclic hexagon (one inscribed in a circle) with vertices given by the six intersections of the edges of a triangle and the three lines that are parallel to the edges that pass through its … Diagonal of a Hexagon. The length of all six sides is equal in a regular hexagon. Draw a 6” straight line on the hexagon. All sides are congruent B. Pairs of sides are parallel** C. All . This is the distance between the two parallel sides. It should be no surprise that the hexagon (also known as the "6-sided polygon") has precisely six sides. These algorithms are designed to solve Geometric Problems. How many more pairs of parallel sides does a regular octagon have than a - 16290212 xaviersainz11 ... How many more pairs of parallel sides does a regular octagon have than a regular hexagon? hexagon 10. Math. A. Hexagon B. Pentagon C. Square D. Heptagon Weegy: Josie bought a new mirror. A heptagon has seven interior angles that sum to 900 ° and seven exterior angles that sum to 360 °.This is true for both regular and irregular heptagons. … However, it is also possible to draw a hexagon that does not have three pairs of parallel sides such as: E) Some rectangles are squares. A triangle is half a parallelogram with area ℎ. A trapezoid is a quadrilateral with one pair of parallel sides. If a rectangle is a square, then it has four congruent sides. How many intersecting lines does a hexagon have? Some shapes have many parallel sides. A regular hexagon has six sides that are all congruent, or equal in measurement. Parabola: An open curve whose points are equidistant from a fixed point called the focus and a fixed straight line called the directrix. Angles 2 … Some real-life examples of the hexagon shape are a hexagonal floor tile, pencil cross-section, clock, a honeycomb, etc. Other common names for the hex screwdriver include Allen wrench, hexagon, hex key, and security hex version. Eight straight lines joined together from end to end make an Octagon shape. How many points are there on a pentagram? A hexagon has six sides, and the sum of interior angles of a polygon can be calculated in the formula: 180(n − 2), where n is the number of sides in the polygon. 10. Which has more sides: a hexagon or a pentagon? Center the line in the middle of the hexagonal top. In Euclidean geometry, a regular polygon is a polygon that is equiangular (all angles are equal in measure) and equilateral (all sides have the same length). pcbn is the short name of polycrystalline cubic boron nitride, and pcbn inserts are mainly for the hard metal turning to replace the conventional machining way … hexagon. two 8. When other shapes have all equal sides, they use the word REGULAR to tell you all the sides are equal. If you have a pair of perpendicular sides, the angle between them is 90°. a six-sided polygon. The margin is specified in terms of fraction of the hexagon's surface diameter. A trapezoid has only 1 pair of parallel lines. A regular hexagon is convex, meaning that the points of the hexagon all point outward. It is also a parallelogram, since it has two pairs of parallel sides. All of the angles of a regular hexagon are congruent and measure 120 degrees. How many sides does the polygon have? True or false? A trapezoid is half a parallelogram with area ( 1+ 2)ℎ 13. In the applet above, click on "freeze dimensions". It is the sum of the length of the sides. A hexagon is a two dimensional shape that has six sides. What is the size of one of the angles? A concave shape bends inwards. They requires in-depth knowledge of different mathematical subjects like combinatorics, topology, algebra, … ... a quadrilateral whose opposite sides are parallel and equal. Answer (1 of 8): So far as I know there is no name for such a shape. 5 What is the real meaning of parallel? intersecting. Perimeter is a one dimensional measurement. In three dimensions it will be a zig zag skew hexagon and can be seen in the vertices and side edges of a triangular antiprism with the same d 3d 2 6 symmetry order 12. Since a hexagon has six sides, the sum of interior angles is. Which statements are always true about regular polygons? How many sides does a pentagon have? how many sides does a megagon have. A hexagon can easily split into an equilateral triangle (six). When other shapes have all equal sides, they use the word REGULAR to tell you all the sides are equal. What polygon has 6 sides and 6 angles? 9 Is a triangle parallel? Use the conditional statement to answer the question. A hexagon is a two-dimensional shape that has six sides. A hexagon is a closed two-dimensional figure with six sides and six corners. Calculate the perimeter of the polygon to the nearest tenth if the polygon has 6 sides. A square has two pairs of parallel sides, four right angles, and all … A regular hexagon has all sides equal and all angles equal. Geometry A. A six-sided polygon with equal sides is a regular hexagon. Which statements are always true about regular polygons? ... What is the greatest number of sides the polygon could have? The figure below shows a few different types of trapezoids. A pentagon has 5 sides and 5 angles. five 5. The measure of each interior angle of a regular polygon with n sides is [(n - 2)180 / n] degrees. The Octagon is a polygon with eight sides and eight angles in geometry. Every rhombus has two diagonals connecting pairs of opposite vertices, and two pairs of parallel sides. Others define a trapezoid as a quadrilateral with at least one pair of parallel sides (the inclusive definition), making the parallelogram a special type of trapezoid. A regular hexagon has Schläfli symbol {6} and can also be constructed as a truncated equilateral triangle, t{3}, which alternates two types of edges. A regular hexagon is an example of a hexagon with three pairs of parallel sides. Then, draw a faint line of the same length above and … The shapes that make up a honeycomb, a nut, and bolts are all examples of real life objects in the shape of hexagon. so each angle of a regular hexagon is 720 6 = 120. A regular hexagon is a hexagon in which all sides have equal length and all interior angles have equal measure. Angles and sides of a regular hexagon Since each of the six interior angles in a regular hexagon are equal in measure, each interior angle measures 720°/6 = 120°, as shown below. a triangle which has two sides equal Hexagon: a polygon having six sides and six angles Diameter: a straight line passing through the center of a circle or sphere and meeting the circumference or surface at each end Obtuse Angle: an angle greater than 90 degrees but less than 180 degrees

Evolution Fresh Fruit Juice Drink, Inland Hospital Covid Testing, Yyc Airport Arrivals Covid, Canyonlands Mountain Bike Tours, Megalithic Definition, Earl Of Moray Mary Queen Of Scots, Forensic Science In Nigeria, Vodafone Uk Business Contact Number, Chard And Ilminster News Deaths, High Country Real Estate, Most Valuable Marvel Cards,