Question: 2 equilateral triangles that are congruent and share a side?
Answer: Congruent triangles sharing a common side To be congruent two triangles must be the same shape and size. However they can share a side, and as long as they are otherwise identical, the triangles are still congruent. In the figure below, the triangle LQR is congruent to PQR even though they share the side QR.