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)
68.8
78.8
88.8
98.8
The sum of the two given angles is 39.5° + 61.7° = 101.2°.
Therefore, the measure of the third angle = 180° - 101.2° = 78.8°.
So, the measure of the third angle is 78.8°.
Therefore, the correct answer is 78.8.