Similar Triangles
We learned several basic tests for determining whether two triangles are congruent. Recall that each congruence test involves only three corresponding parts of each triangle. Likewise, there are tests for similarity that will not involve all the parts of each triangle.
Angle-Angle (AA) Similarity
If two angles of one triangle are congruent to two angles of another triangle, then the triangles are similar.
Side-Side-Side (SSS) Similarity
If all the measures of the corresponding sides of two triangles are proportional, then the triangles are similar.
Side-Angle-Side (SAS) Similarity
If the measures of two sides of a triangle are proportional to the measures of two corresponding side of another triangle and the included angles are congruent, then the triangles are similar.
Find out more about similar triangles by reading the explanation below.
Practice: Use the AA, SSS, and SAS similarity tests for triangles in answering the exercises below.