# CBSE NCERT Solutions for Class 8 Chapter 3

NCERT Solutions are prepared by experts to provide accurate and easy solutions for all questions covered in class 6 to 10 NCERT textbooks. Students get step-by-step explanation to every question specified in the textbooks.

**CBSE NCERT Solutions for Class 8 Maths Chapter 3:**

*Question-1*:

Find the measure of each exterior angle of a regular polygon of:

(a) 9 sides (b) 15 sides

*Solution*:

(i) Sum of angles of a regular polygon = (n-2) x 1800

=(9-2)x1800

=7x1800

= 12600

Each interior angle = sum of interior angle /number of sides = 12600/9 = 1400

Each exterior angle = 1800– 1400= 400

(ii) Sum of exterior angles of a regular polygon = 3600

Each Exterior angle of a regular polygon has the same measure.

Thus , measure of each exterior angle angle of a regular polygon of 15sides

= 360o/15 = 24o

*Question-2*:

How many sides does a regular polygon have, if the measure of an exterior angle is 240?

*Solution*:

Let number of sides be n.

Sum of exterior angles of a regular polygon = 3600

Number of sides = sum of interior angle /number of sides = 3600/24 = 15

Hence, the regular polygon has 15 sides.

*Question-3*:

How many sides does a regular polygon have if each of its interior angle as 1650?

*Solution*:

Let number of sides be n.

Exterior angle = 1800– 1650= 150

Sum of exterior angles of a regular polygon = 3600

Number of sides = sum of interior angle /number of sides = 3600/15 = 25

Hence, the regular polygon has 24 sides.

*Question-4*:

(a) How many sides does a regular polygon have if each of its interior angle as 220?

(b) Can it be an interior angle of a regular polygon? Why?

*Solution*:

(a) No. ( Since 22 is not a divisor of 3600)

(b) No, ( Because each exterior angle is 1800– 220= 1580 , which is not a divisor of 360