NCERT Solutions Class 8th Maths Chapter – 3 Understanding Quadrilaterals Exercise – 3.1

1. Given here are some figures. Here are some data, classify each of them on the basis of the following. (a) Simple Curve (b) Simple Closed Curve (c) Polygon (d) Convex Polygon (i) Concave Polygon

Classify each of them on the basis of the following.

(a) Simple Curve (b) Simple Closed Curve (c) Polygon (d) Convex Polygon (i) Concave Polygon

Solution:

a) Simple curves: 1, 2, 5, 6 and 7

b) Simple closed curves: 1, 2, 5, 6 and 7

c) Polygons: 1 and 2

d) Convex polygons: 2

e) Concave polygons: 1

5. What is a regular polygon? State the name of a regular polygon of

(i) 3 sides
(ii) 4 sides
(iii) 6 sides

Solution:

Regular polygon: A polygon with angles of equal length and equal measure is called a regular polygon. That is, a regular polygon is both equilateral and right-angled.

(i) A regular polygon of 3 sides is called an equilateral triangle.

(ii) A regular polygon of 4 sides is called a square.

(iii) A regular polygon of 6 sides is called a regular hexagon.