Question

15. Find ‘y’ in each of the following figures :​

Answer 1

i) y = 180° - 150° = 30°

ii) 3y + 5y = 180°

8y = 180°

y = 180/8

iii) 90° + y + 3y + 2y = 360°

90° + 6y = 360°

6y = 360° - 90°

6y = 270

y = 270/6 = 45°

iv) <COA + <AOD = 180° [ COD is a line]

y + 55° = 180°

y = 180° - 55°

= 125°

v) <AOB + <BOC + <COD = 180° [AOD is a line]

70° + 3y + 50° = 180°

120° + 3y = 180°

3y = 180° - 120°

= 60°

y = 60/3 = 20°

vi) 120° + 4y = 180°

4y = 180 - 120 = 60°

y = 60/4 = 20°