Question

two similar triangle are proportional to the squares of their perimeter​

Answer 1

we have two similar triangles, then not only their angles and sides share a relationship but also the ratio of their perimeter, altitudes, angle bisectors, areas and other aspects are in ratio.

In the upcoming discussion, the relation between the areas of two similar triangles is discussed.

Answer 2

Area Of Similar Triangles and Its Theorems CBSE Class 10 - Byju's Theorem: If two triangles are similar, then the ratio of the area of both triangles is proportional to the square of the ratio of their corresponding sides. This proves that the ratio of areas of two similar triangles is proportional to the squares of the corresponding sides of both the triangles.