## Geometry: Common Core (15th Edition)

$\angle$CHB and $\angle$BHA
$\angle$CHB, $\angle$BHA, and $\angle$AHG form a straight angle. This means that these three angles, when added together, equal 180$^{\circ}$. $\angle$AHG is labelled with a right angle, which means that $\angle$AHG has an angle measure of 90$^{\circ}$. If m$\angle$AHG is 90, then the other two angles must also equal 90 when added together. As complementary angles equal 90$^{\circ}$, and $\angle$CHB and $\angle$BHA equal 90$^{\circ}$, these two angles are adjacent complimentary angles.