The areas of similar triangles 'DeltaABC' and 'DeltaDEF' are equal. If the longest side of 'DeltaDEF' measures 25 units, what is the length of the longest side of 'DeltaABC'?

A.

5 units

B.

25 units

C.

50 units

D.

75 units

There is a theorem which states that "If the areas of two similar triangles are equal then the triangles are congruent."

So, the longest side of Δ DEF will be congruent to ΔABC.

Longest side of Δ DEF ≡ Longest side of ΔABC.

Suppose in the diagram, the longest side of the Δ DEF is EF and longest side of Δ ABC is BC.

So, EF = BC

Since, EF = 25 units is given.

So, BC = 25 units.

Hence, longest side of triangle ABC is 25 units.