Two supplementary angles always adds up to 180 degrees. If an angle is 67.2 degrees less than the measure of a supplementary angle, an equation can be formed where "A" represents the larger angle, and (A - 67.2) represents the smaller angle.
(A - 67.2)+A=180
(Combine the A's)
2A - 67.2=180
(Add 67.2 to both sides)
2A = 247.2
(Divide by 2 to both sides)
A = 123.6
123.6 degrees is the larger angle.
The smaller angle is represented by (A - 67.2). We now know the value of A so lets plug it in. (123.6 - 67.2) = 56.4. 56.4 is the value of the smaller angle.
We can double check to make sure we got the right answer.