The corresponding sides of two similar triangles ABC and DEF are BC =

1.	The corresponding sides of two similar triangles ABC and DEF are BC = 9.1cm and EF = 6.5cm. If the perimeter of ∆DEF is 25cm, find the perimeter of ∆ABC.
Answer» It is given that ∆ ABC - ∆ 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 ∆ABC/ perimeter of ∆DEF = BC/EF Let the perimeter of ∆ABC be X cm Therefore, X/25 = 9.1/6.5 ⇒ X = 9.1×25/6.5 = 35 Thus, the perimeter of ∆ABC is 35 cm.

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

Answer»

It is given that ∆ ABC - ∆ 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 ∆ABC/ perimeter of ∆DEF = BC/EF

Let the perimeter of ∆ABC be X cm

Therefore,

X/25 = 9.1/6.5

⇒ X = 9.1×25/6.5 = 35

Thus, the perimeter of ∆ABC is 35 cm.