Question

AB is parallel to CD.

Answer 1

Answer:

Step-by-step explanation:

∠ABC = ∠BCD    { AB // CD; BC TRAVERSAL, alternate angles are equal}

∠ABC = 20

∠BCA = ∠BAC     {angles opposite to equal sides are equal}

∠BCA = ∠BAC = x

x + x + 20 = 180

2x = 180 - 20

2x = 160

x = 160/2

x = 80