Question

Find the measure of the indicated angle.

S
3x +5°
mZR=
2x +7°
0
T
R

Answer 1

74°

Explanation:

As SR = RT, the angles opposing them are equal.

• ∠S = ∠T

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°