Question

2. Given: mZABD = rº and mZACB = yo

Answer 1

Step-by-step explanation:

the angle ABC = 180 - x, as ABD and ABC are complementary angles on top of the bottom line : all angles around a point on one side of a line are always adding up to 180 degrees.

but because we also know that the sum of all angles in a triangle is 180 degrees too, we can say

180 = ACB + ABC + CAB

180 = y + 180 - x + CAB

0 = y - x + CAB

x = y + CAB

x - y = CAB

therefore, the second answer option is correct.