Question

How to find y in angle sum theorem

Answer 1

y = 90°

Explanation:

• 110° is the measure of exterior angle of bigger triangle.

• -> (x + x) + 70° = 110° (By exterior angle theorem)

• -> 2x = 110° - 70°

• -> 2x = 40°

• -> x = 40°/2

• -> x = 20°

• y is the measure of exterior angle of smaller triangle.

• -> y = x + 70° (By exterior angle theorem)

• -> y = 20° + 70°

• -> y = 90°