Question

What is the perimeter of a rectangle with one side 3cm if it had a area of 21cm?

Answer 1

The perimeter is 20 cm.

Explanation:

Let the one side of the rectangle is `=a`
Let the other side of the rectangle is `=b`
Then area `= a xx b=ab`
Now -

Let `a = 3 cm`
`3b=21`
`b=21/3=7`

The perimeter of the rectangle `=2(a+b)=2(3+7)=2(10)=20`