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Think of the 20 identical triangles that are formed inside the polygon when you draw line segments from the centre of the polygon to each of the polygons corners.
The angles of those triangles at the centre of the polygon add to 360 degrees, and there are 20 of them. Therefore, each of the angles of the triangles at the centre is 360 / 20 = 18 degrees.
The angles within each triangle add to 180 degrees. Therefore the other two angles within each triangle, away from the centre of the polygon, add to 180 - 18 = 162 degrees. The two angles are equal. Therefore each angle is 162 / 2 = 81 degrees.
Each interior angle of the 20-sided polygon consists of two of these angles. Therefore, the interior angle is 2 x 81 or 162 degrees.
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What is the size of an interior angle of a 20 sided regular polygon?
exterior angle = 360° ÷ 20 sides = 18° interior angle = 180° - exterior angle = 180° - 18° = 162°
What is the sum of the interior angles of a twenty sided polygon?
Use the formula below to calculate the sum of the interior angles of any polygon with n-number of sides: n * (180o) - 360o or (n-2) * 180o And to find the measurement of each interior angle divide this number by the number of sides of the polygon. So for a 20-sided polygon, the sum of the interior angles would be: 20*180o - 3600 = 3240o or (20-2) * 180o = 3240o And each interior angle would measure 3240o/20 or 162o == ==
What is the names of shapes with 13 to 20 sides?
Shapes with 13 to 20 sides are known as polygons. Specifically, a 13-sided polygon is called a tridecagon, a 14-sided polygon is called a tetrakaidecagon, a 15-sided polygon is called a pentadecagon, a 16-sided polygon is called a hexadecagon, a 17-sided polygon is called a heptadecagon, an 18-sided polygon is called an octadecagon, a 19-sided polygon is called an enneadecagon, and a 20-sided polygon is called an icosagon.
Find the number of sides a regular polygon must have to meet each condition each exterior angle measure is one eigth the measure of each interior angle?
An exterior angle of a regular polygon and its corresponding interior angle = 180° If an exterior angle is 1/8 of the interior angle (A) then A + A/8 = 180 : 9A = 1440 : A = 160 Each exterior angle is thus 180 -160 = 20° The number of sides = 360 ÷ exterior angle = 360 ÷ 20 = 18
What is the exterior angle of an 18 sided shape?
The exterior angle of a 18 sided shape is 360/18 =20 degrees The exterior angle is always 360 divided by the numbe of sides of that polygon. =) what the hell im i doing answering this?
