Answer:
∠8 * 4 = ∠7 ----------------(1)
∠8 + ∠7 = 180 ------------(2)
Taking the value of ∠7 from (1) and using it in (2):
∠7 = 4 * ∠8
∠8 + ∠7 = 180
∠8 + (4 * ∠8) = 180
∠8 + 4∠8 = 180
5∠8 = 180
∠8 = 36° ---------------(3)
Using the value of ∠8 from (3) in (2):
∠8 + ∠7 = 180
36 + ∠7 = 180
∠7 = 144° and ∠8 = 36°
