Respuesta :

Answer:

74°

Step-by-step 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°