Two angles of a triangle measure 39.5° and 61.7° . Use the Triangle Angle Sum Theorem to find the measure of the third angle; do not round the answer.(1 point)

Question

Responses

79°
79 degrees

68.8°
68.8 degrees

78.8°
78.8 degrees

78°

Answer 1

The Triangle Angle Sum Theorem states that the sum of the angles in a triangle is always 180°.

To find the third angle, we can use the following equation:

\[ \text{Third Angle} = 180° - (\text{First Angle} + \text{Second Angle}) \]

Given the measures of the first two angles:

\[ \text{First Angle} = 39.5° \] \[ \text{Second Angle} = 61.7° \]

Now, add these two angles:

\[ 39.5° + 61.7° = 101.2° \]

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

\[ \text{Third Angle} = 180° - 101.2° = 78.8° \]

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