NCERT Solution class 7 Mathematics EXERCISE- 6.2
CHAPTER – 6
EXERCISE – 6.2
Q1. Find the value of the unknown exterior angle x in the following diagrams:
SOLUTION:-
(i) We know that.
An exterior angle of a triangle is equal to the sum of its interior opposite angles.
= x = 500 + 700
= x = 1200
(ii) We know that,
An exterior angle of a triangle is equal to the sum of its interior opposite angles
= x = 650 + 450
= x = 1100
(iii) We know that,
An exterior angle of a triangle is equal to the sum of its interior opposite angles.
= x = 300 + 400
= x = 700
(iv) We know that,
An exterior angle of a triangle is equal to the sum of its interior opposite angles.
= x = 600 + 600
= x = 1200
(v) We know that,
An exterior angle of a triangle is equal to the sum of its interior opposite angles.
= x = 500 + 500
= x = 1000
(vi) We know that,
An exterior angle of a triangle is equal to the sum of its interior opposite angles.
= x = 300 + 600
= x = 900
Q2. Find the value of the unknown interior angle x in the following figures
SOLUTION:-
(i) We know that,
An exterior angle of a triangle is equal to the sum of its interior opposite angle
= x + 500 = 1150
= x = 1150 – 500
= x = 650
(ii) We know that,
An exterior angle of a triangle is equal to the sum of its interior opposite angles.
= 700 + x = 1000
= x = 1000 – 700
= x = 300
(iii) We know that,
An exterior angle of a triangle is equal to the sum of its interior opposite angles.
The given triangle is a right angled triangle. So the angle opposite to the x is 900
= x + 900 = 1250
= x = 1250 – 900
= x = 350.
(iv) We know that,
An exterior angle of a triangle is equal to the sum of its interior opposite angles.
= x + 600 = 1200
= x = 1200 – 600
= x = 600.
(v) We know that,
An exterior angle of a triangle is equal to the sum of its interior opposite angles
= x + 300 = 800
= x = 800 – 300
= x = 500
(vi) We know that,
An exterior angle of a triangle is equal to the sum of its interior opposite angles
= x + 350 = 750
= x = 750 – 350
= x = 400