Respuesta :

Answer:

166°

Step-by-step explanation:

Since ∠A = ∠B,

the equation below helps to find the value of x and angle A:

  • 7x + 40° = 3x + 112°
  • 7x - 3x = 112° - 40°
  • 4x = 72°
  • x = 72°/4
  • x = 18°
  • ∠A = 7*18° + 40° = 166°

7x+40-180=3x+112-180

7x-3x=112-40

4x=72

x=18

A=7*18+40=126

B=21+112=133