Question

if triangle ABC is congurant to triangle QRP ar(triangle ABC)/ar(triangle QRP) =9/4,BC is 15 cm then find the length of PR​

Answer 1

Answer:

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 = AB

2

QR

2

= Bc

2

PR

2

= AC

2

QP

2

So, we take

Area of ∆ ABC Area of ∆ QRP = BC

2

PR

2

Now substitute all given values and get

94 = 152PR2

Taking square root on both hand side, we get

32 = 15PR

PR = 10 cm