Question

Find the length of a rectangle as shown in the adjoining figure, if
its perimeter is 100 metres and breadth is 20 metres.​

Answer 1

Answer:

perimeter=2l+2b(l-length,b-breadth)

100=2l+2(20)

2l=60

l=30m

Answer 2

Given:

A rectangle with

• Perimeter = 100 m
• Breadth = 20 m

What to find?

We have to find the length of the rectangle.

How to find?

To find the length of the rectangle we will use the formula Perimeter = 2(l + b) and substitute and solve.

Solution:

Using the formula,

⇒ Perimeter = 2(l + b)

Substitute the values,

⇒ 100 = 2(l + 20)

Remove the brackets,

⇒ 100 = 2l + 40

Take 40 to LHS,

⇒ 100 - 40 = 2l

Subtract 40 from 100,

⇒ 60 = 2l

Take 2 to LHS,

⇒ $\dfrac{60}{2}$ = l

Divide 60 by 2,

⇒ 30 = l

∴ So, the length of the rectangle is 30 m.