Answer:
x = 20; ∠5 = 120°
Step-by-step explanation:
∠1 and ∠8 are alternate angles and therefore are equal, which means that if m ∠1 = (4x + 40)° and m ∠8 = (2x + 80)°, then 4x + 40 = 2x + 80
Solve for x:
4x + 40 = 2x + 80
2x = 40
x = 20
∠5 is corresponding to ∠1 and vertical to ∠8, therefore equal to both; To find it's measure:
Plug x into either ∠1 or ∠8's respective equations:
2x + 80
2(20) + 80
120
∠5 is 120°
