Triangle Similarity: Angle Angle

Recall Recall the definitions of the following: Similar Congruent Also recall the properties of similarity we discussed yesterday Corresponding angles in similar figures are congruent The ratio of corresponding sides in a figure are equal

There’s another way There are other ways to prove figures are similar Today we are looking at triangle similarity Mainly involving the angle-angle similarity postulate

Angle-Angle similarity postulate If two angles of one triangle are congruent to two angles of another triangle, then the two triangles are similar This postulate allows you to say that two triangles are similar if you know that two pairs of angles are congruent. You don’t need to compare all of the side lengths and angle measures to show that two triangles are similar.

Third Angle Theorem If two angles in one triangle are congruent to two angles in another triangle, then the third angles must be congruent also.

Using the AA similarity postulate Determine whether the triangles are similar. If they are similar, write a similarity statement. Explain your reasoning.

Using the AA similarity postulate Are you given enough information to show that ∆RST is similar to ∆RUV? Explain your reasoning.

Determine whether the triangles are similar. If they are similar, write a similarity statement.

Using AA postulate to find the missing side