Your friend claims isosceles triangles are congruent if two corresponding sides are congruent. He explains there are only two different lengths of sides, so the third side must always be congruent. Explain the error in his reasoning.

Question

anonymous · Answer

The third side cannot be congruent it could be of any length, but note two  isosceles triangles are always similar.

anonymous · Answer

For a technical answer you write, congruency of two sides doesn't imply congruency of the included angle or the third side. Hence the flaw.

anonymous · Answer

can*

anonymous · Answer

perfect(: