## Elementary Geometry for College Students (7th Edition)

According to the Angle-Angle (AA) Similarity Postulate, $\triangle DGH$ ~ $\triangle DEF$
Angle-Angle (AA) Similarity Postulate: If two angles of a triangle are congruent to two angles of another triangle, then the two triangles are similar. $\angle DGH \cong \angle DEF$ We can see that $\angle GDH$ and $\angle EDF$ are the same angle. Therefore two angles in the triangles are congruent. According to the Angle-Angle (AA) Similarity Postulate, $\triangle DGH$ ~ $\triangle DEF$