Start with congruencies of 130°:
∠1 and 130° are vertical angles
∠2 and 130° are corresponding angles
∠5 and 130° are alternate exterior angles
m∠1 = m∠2 = m∠5 = 130°
∠7 and 130° are supplementary angles (which means their sum is 180°). So, ∠7 = 50°
Next, find congruencies of ∠7:
∠3 and ∠7 are vertical angles
∠4 and ∠7 are corresponding angles
∠6 and ∠7 are alternate exterior angles
m∠3 = m∠4 = m∠6 = m∠7 = 50°
Answer: B
