Two angles of a triangle are 23° and 86°. Find the measure of the third angle.
A) 157°
B) 94°
C) 243°
D) 71°
E) 117°

Question

Quizplus · Accepted Answer

The angle measures of a triangle add up to 180°. Therefore, the measure of the third angle can be found by subtracting the sum of the two given angles from 180°:

180° - (23° + 86°) = 71°

Therefore, the measure of the third angle is 71°, which corresponds to choice D.

Two Angles of a Triangle Are 23° and 86°