## Geometry: Common Core (15th Edition)

We are given the measures of two sides and an included angle in the two triangles. Let's see if the Side-Angle-Side Similarity Theorem can be applied here. The SAS Similarity Theorem states that if two sides in one triangle are proportional to the two sides of another triangle, and the included angle in one triangle is congruent to the included angle of the other triangle, then the two triangles are similar. Let's set up the ratios of corresponding sides in $\triangle MPR$ and $\triangle NAD$: $\frac{MP}{NA} = \frac{6}{6}$ Divide both the numerator and denominator by their greatest common factor, $6$: $\frac{MP}{NA} = \frac{1}{1}$ Let's look at $PR$ and $AD$: $\frac{PR}{AD} = \frac{10}{8}$ Divide both the numerator and denominator by their greatest common factor, $2$: $\frac{PR}{AD} = \frac{5}{4}$ Let's look at the corresponding angles in the two triangles: $m \angle G ≅ m \angle E = 90^{\circ}$ No, the triangles are not similar because although the included angle is congruent, the scale factors for the two sides in each triangle that are given are not the same. This means that the two sides in one triangle are not proportional to the two sides in the other triangle.