Question

The areas of two similar triangles ΔABC and ΔDEF are 144 cm² and 81 cm² respectively. If the longest side of larger ΔABC be 36 cm, then. the longest side of the smaller triangle ΔDEF is 

A. 20 cm 

B. 26 cm 

C. 27 cm 

D. 30 cm

Answer 1

Given that area of two similar triangles ΔABC and ΔDEF are 144 cm² and 81 cm². Also the longest side of larger ΔABC is 36 cm. 

We have to find the longest side of the smaller triangle ΔDEF. Let it be x. 

We know that the ratio of areas of two similar triangles is equal to the square of the ratio of their corresponding sides.

⇒ x = 27 cm 

∴ Longest side of ΔDEF is 27 cm.