Answer:
74°
Step-by-step explanation:
As SR = RT, the angles opposing them are equal.
Applying the Angle Sum Property :
- ∠R + ∠S + ∠T = 180°
- ∠R + 2∠S = 180°
- (3x + 5)° + 2(2x + 7)° = 180°
- 3x + 5 + 4x + 14 = 180
- 7x + 19 = 180
- 7x = 161
- x = 23
Finding m∠R :
- ∠R = 3(23) + 5
- ∠R = 69 + 5
- ∠R = 74°
