Question

the length of a rectangle is 7/5 of its breadth.If its perimeter is 48cm ,then what is its length?

Answer 1

L=7/5×b

B=b

Perimeter=L+B

7/5×b+b

b (7/5+1)

b (12/5)=48

b=48×5/12

B=20cm

L=7/5×20

L=28cm

Answer 2

Given - perimeter

Find - Length of rectangle

Solution - The length of the rectangle is 14 centimetres

Let the breadth of the rectangle be x. So, the length of the rectangle = 7x/5

The perimeter of the rectangle is given by the formula - 2(length + breadth).

Keeping the values in the formula to find the value of x

48 = 2(7x/5 + x)

48/2 = 7x + 5x/5

24*5 = 12x

12x = 120

x = 120/12

x = 10

So, the breadth of the rectangle be 10 centimetres

The length of the rectangle = 7*10/5

The length of the rectangle = 70/5

The length of the rectangle = 14 centimetres

Hence, the length of the rectangle is 14 centimetres.