Answer:
x = 4 , ∠ A = 65° , ∠ B = 88° , ∠ C = 23°
Step-by-step explanation:
∠ A + ∠ C = 88 , substitute values for A and C
5x + 3 + 15x + 5 = 88
20x + 8 = 88 ( subtract 8 from both sides )
20x = 80 ( divide both sides by 20 )
x = 4
Then
∠ A = 15x + 5 = 15(4) + 5 = 60 + 5 = 65°
∠ A + ∠ C = 88° , that is
65° + ∠ C = 88° ( subtract 65° from both sides )
∠ C = 23°
∠ B = ∠ A + ∠ C ( vertically opposite angles )
∠ B = 88°
