Question

In a square sheet, there are two triangles of equal area such that the triangles are congruent. What can you say about their perimeters?

Answer 1

In a squared sheet, lets say we have $\Delta ABC$ and $\Delta PQR$.
It is given that both these triangles have equal areas and they are congruent.
Since both the triangles are congruent, lengths of sides of one triangle is equal to the corresponding lengths of sides of another triangle by SSS congruence rule.
That means the perimeter of both $\Delta ABC$ and $\Delta PQR$ is equal.