Question

Two angles of a triangle measure 120 and 40°.

What is the measure of the third angle of the triangle?

Answer 1

Answer: 20°

the measure of the third angle of the triangle is x ( 0 < x < 90)

because this is 3 angles in a triangle, we have:

120 + 40 + x = 180

⇔ x = 180 - 120 - 40

⇔ x = 20°

Explanation: