ABCD is a parallelogram. Explain why ABC is congruent to ACD

Question

 Explain: why triangles ABC and ACD are congruent in a parallelogramn.

The parallelogramm is ABCD

Answer 1

Hi Paul,

Since opposite sides of a parallelogram are congruent, then AB≅CD and BC≅AD and the diagonal AC is congruent to itself, so the triangles ABC and ACD are congruent by SSS congruency theorem.