Question

The measure of an angle is 112.8°. What is the measure of its supplementary angle?

Im D u m b

Answer 1

If angles X and Y are supplementary
X+Y=90
x=16+3y
16+3y+y=90
4y=90-16
4y=74
y=74/4=18.50
x=90-18.50=71.50

Answer 2

Supplementary angels means that they both add up to 180°. So 112.8+x=180.
So subtract 112.8 from both sides and you get 67.2°. So the answer is 67.2°