Answer:
Step-by-step explanation:
Sum of angles in a triangle = 180
1. 180 = 78 + 37 + x
180 = 115 + x
Subtract 115 from both sides
180 - 115 = 115 + x - 115
180 - 115 = x
65 = x
x = 65°
2. 180 = 80 + 66 + x
180 = 146 + x
Subtract 146 from both sides
180 - 146 = 146 + x - 146
34 = x
x = 34°
