
To find the measure of ∠ABC, we need to know that the sum of the interior angles of a triangle is 180º.

Triangle CED has two given angles: 65º and 50º. We can add them together and subtract that from 180 to get the third measure.


Since lines AB and ED are parallel, that means m∠ACB is also 65º since the vertical angle is also 65º. Then, we can add 65 and 50 together and subtract that from 180 to get our answer.

