Question

"Question 6 Find the angle measure x in the following figures. (a) (b) (c) (d)

Class 8 Understanding Quadrilaterals Page 42"

Answer 1

 A simple closed curve made up of only line segments is called a polygon

A regular polygon is a polygon that is equiangular (all angles are equal in measure) and equilateral (all sides have the same length).

Convex Polygon
We have all the diagonals inside the Polygon.

Concave Polygon
We don’t have all the diagonals inside the Polygon.

 

A quadrilateral is a four sides Polygon. It has four angles.

A diagonal is a line segment connecting two non-consecutive vertices of a polygon

 
Angle Sum Property

The sum of the measures of the interior angles of a quadrilateral is=360°

the sum of the measures of the exterior angles of any polygon is 360°.

The sum of the measures of the interior angles of a pentagon is=540°

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Solution of figure i , ii, iii are  in the attachment....

iv) The sum of the measures of the interior angles of a pentagon is 540°

5x = 540°

x= 540/5 

x= 108°

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Hope this will help you...