Plz Help! I don't know how to solve this. The measures of two angles of a triangle are given. Find the measure of the third angle.
147° 12′, 30° 19′
51° 20′ 14″, 106° 10′ 12″

Example: Applying the Angle Sum of a Triangle Property
The measures of two of the angles of a triangle are 48° and 61°. See Figure 17.
Find the measure of the third angle, x.
SOLUTION 48° + 61° + x = 180° The sum of the angles is 180°.
109° + x = 180° Add.
x = 71° Subtract 109°.
The third angle of the triangle measures 71°.