## Geometry: Common Core (15th Edition)

Let a be the measure of the angle. The measure of the complement is $90-a$. The measure of the supplement is $180-a$. Convert the sentence to an expression. $(90-a)+(180-a)=200$ combine like terms $270-2a=200$ subtract 270 from each side $270-2a-270=200-270$ $-2a=-70$ divide each side by -2 $-2a\div -2=-70\div -2$ $a=35$