Answer:
Step-by-step explanation:
2) ∠A + ∠B = 146 {Exterior angle theorem}
5y + 3 + 4y + 8 = 146
5y + 4y + 3 + 8 = 146 {combine like terms}
9y + 11 = 146
9y = 146 -11
9y = 135
y = 135/9
y = 15
3) m∠A = 5y + 3
= 5*15 + 3
= 75 + 3
∠A = 78
4) m∠B = 4y + 8
= 4*15 + 8
= 60 + 8
m∠B = 68
5) m∠ACB + m∠A + m∠B = 180 {Angle sum property of triangle}
m∠ACB + 78 + 68 = 180
m∠ACB + 146 = 180
m∠ACB = 180 - 146
m∠ACB = 34
