Question

Which of the following is not a valid congruence criterion for triangles?

• A. RHS
• B. SSS
• C. AAA
• D. SAS

Answer 1

The correct option is C AAA

Angle-angle-angle (AAA) is not a valid criterion for congruency of triangles. If two triangles have equal angles, then the triangles are similar, but not congruent.
For example consider two equilateral triangles of sides 3 cm and 5 cm respectively. All their angles measure ${60}^o$, but they are not congruent as their sides are not equal.