Question

45°
(2x - 50
80°
X
115°
X
(1)
1. Find the value of x in each of the following diagrams:​

Answer 1

i) Sum of exterior angle is equal to sum of opposite interior angles,

So,

115° = 2x -5° + x

115° = 3x - 5°

3x = 115° + 5°

3x = 120°

x = 120° / 3

x = 40°

ii) Two angles of a triangle = 80° and x°

Third angle = 45° (alternate angles)

Sum of all angles of a triangle = 180°

So,

80° + x + 45° = 180°

125° + x = 180°

x = 180° - 125°

x = 55°