Question

If triangle ABC similar to triangle QRP ar (ABC)/ar (PQR)=9/4 AB=18cm and BC=15cm find length of PR

Answer 1

Given :

Area of ∆ ABCArea of ∆QRP = 94


AB = 18 cm , BC = 15 cm So PR = ?

We know when two triangles are similar then " The areas of two similar triangles are proportional to the squares of their corresponding sides.

Area of ∆ ABCArea of ∆ QRP = AB2QR2 = BC2PR2 = AC2QP2
So , we take
Area of ∆ ABCArea of ∆ QRP = BC2PR2

Now substitute all given values and get

94 = 152PR2

Taking square root on both hand side , we get

32 = 15PR

PR = 10 cm

hope it helps you