Answer:
Step-by-step explanation:
Both angles added together = 180 degrees. They both have a straight line as their base.
So let <ABC = x
Then <CBD = 3x Add the two angles
x + 3x = 180 Combine
4x = 180 Divide by 4
4x/4 = 180/4
x = 45
So 3x = 3*45 = 135
