Haryana State Board HBSE 7th Class Maths Solutions Chapter 6 The Triangles and Its Properties Ex 6.2 Textbook Exercise Questions and Answers.
Haryana Board 7th Class Maths Solutions Chapter 6 The Triangles and Its Properties Exercise 6.2
Question 1.
Find the value of the unknown exterior angle x in the following diagrams:
Solution:
Since the external angle of a traingle is equal to the sum of the sum of its interior opposite angles. Hence
(i) x° = ∠50° + ∠70° = ∠120°
(ii) x° = ∠65° + ∠45° = 110°
(iii) x° = ∠30° + ∠40° = 70°
(iv) x° = ∠60° + ∠60° = 120°
(v) x° = ∠50° + ∠50° = 100°
(vi) x° = ∠30° + ∠60° = 90°.
Question 2.
find the value of the unknown interior angle x in the following diagrams:
Solution:
external angle = sum of interior angle
(i) Hence 115° = angle x° + 50°
or, 115°-50° = x°
65° = x°
∴ x° = 65°.
(ii) 30° + x° = 100°
or, x° = 100°-30
∴ x° = 70°.
(iii) x° + 90° = 125°
or, x° = 125°- 90′
x° = 35°.
(iv) 60° + x° = 120°
or, x° = 120°-60°
∴ x° = 60°.
(v) 30° + x° = 80°
x° = 80° – 30°
∴ x° = 50°.
(vi) x° + 35° = 75°
or, x° = 75° – 35°
∴ x° = 40°