Chapter 6 · Question 3

State the AA similarity criterion for triangles.

Answer

Direct Answer

If two angles of one triangle are respectively equal to two angles of another triangle, then the two triangles are similar.

Simple Explanation

Two matching angles are enough for triangle similarity.

Exam-Ready Structure

If

\angle A=\angle P

and

\angle B=\angle Q

in triangles

ABC

and

PQR

, then the third angles are also equal by angle sum property. Hence the triangles are equiangular and their corresponding sides are proportional. Therefore

\triangle ABC\sim\triangle PQR

.

Key Points

If two angles of one triangle are respectively equal to two angles of another triangle, then the two triangles are similar.