Question

The corresponding sides of two similar triangles ABC and DEF are BC = 9.1cm and EF = 6.5cm. If the perimeter of ΔDEF is 25cm, find the perimeter of ΔABC. 

Answer 1

It is given that Δ ABC - Δ DEF.
Therefore, their corresponding sides will be proportional.
Also, the ratio of the perimeters of similar triangles is same as the ratio of their corresponding sides. 

⇒ `("Perimeter of ΔABC")/("Perimete of ΔDEF")=(BC)/(EF)`  

Let the perimeter of ΔABC be X cm Therefore, 

`x/25=9.1/6.5` 

`⇒x=(9.1xx25)/6.5=35`

Thus, the perimeter of ΔABC is 35 cm.