Question

The length of a rectangle is two times of its breadth. If the perimeter is 36 CM then find its area.

Answer 1

Let the breadth of rectangle be x cm.

Then length will be :- 2x cm

Perimeter = 2 (l+b)

$36 = 2(2x + x) \\ \\ \frac{36}{2} = 3x \\ \\ 18 = 3x \\ \\ x = \frac{18}{3} \\ \\ x = 6 \: cm$

So,

Breadth = x = 6 cm

Length = 2x = 12 cm

$area \: = l \: \times \: b \\ \\ = 6 \times 12 \\ \\ area \: = 72 \: {cm}^{2}$

Hope it helps.

Answer 2

By Step by Step method :-

Let the breadth = 'b'

Let the Length = '2b',

So,

P=2(l+b)

By Substituting,

36cm=2(2b+b)

36cm=2(3b)

36cm=6b

Therefore,

6b=36cm

b=36cm/6

b=6cm

Answer :-

Length is,

2b = 2*6 = 12cm

Breadth is,

b = 6cm