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

68.8°
68.8°

78.8°
78.8°

88.8°
88.8°

98.8°

1 answer

To find the measure of the third angle in the triangle, you can use the Triangle Angle Sum Theorem, which states that the sum of the angles in a triangle is always 180°.

Given the two angles:

  • First angle = 39.5°
  • Second angle = 61.7°

First, add the two angles together:

\( 39.5° + 61.7° = 101.2° \)

Now, subtract this sum from 180° to find the measure of the third angle:

\( 180° - 101.2° = 78.8° \)

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