## Geometry: Common Core (15th Edition)

The two labeled angles measure: $x=115$ $x-50=65$
The angle marked $x$ forms an same-side interior angle pair with the angle marked $x-50$. The same-side interior angle theorem tells us these two angles are supplementary. $x+(x-50)=180\longrightarrow$ definition of supplementary $2x-50=180\longrightarrow$ combine like terms $2x=230\longrightarrow$ addition property of equality $x=115\longrightarrow$ division property of equality Substitute to find the measure of the other angle. $x-50=115-50=65$