Notice that there is a triangle with two of the angles given. We know that the sum of any triangle's angles will always be 180°. Thus, we can subtract the two given angles from 180, and that will give us the measure of angle ABC.
Notice that there is a triangle with two of the angles given. We know that the sum of any triangle's angles will always be 180°. Thus, we can subtract the two given angles from 180, and that will give us the measure of angle ABC.