Two angles of a triangle measure 39.5° and 61.7°. Using the Triangle Angle Sum Theorem, which states that the sum of the inside angles of all triangles must equal 180°, find the measure of the third angle. (2 points)

Question

Two angles of a triangle measure 39.5° and 61.7°. Using the Triangle Angle Sum Theorem, which states that the sum of the inside angles of all triangles must equal 180°, find the measure of the third angle. (2 points)
Responses

A. 68.8°
68.8°

B. 78.8°
78.8°

C. 88.8°
88.8°

D. 98.8°

GPT 3.5 · Answer

The measure of the third angle is found by subtracting the sum of the two given angles from 180°:

180° - (39.5° + 61.7°) = 78.8°.

Therefore, the measure of the third angle is 78.8°.

Correct Response: B. 78.8°