Question

The side of a square is 10 cm. What is the increase in area in percentage if the side is lengthened by 3 cm.

Answer 1

Answer: 69%

Explanation:

10 cm

Find the area.
`A=s^2`

`A=(10cm)^2\\A=100cm^2`

Now calculate the area when a side is lengthened by 3 cm.

10+3=13 cm

`A=s^2\\A=(13cm)^2\\A=169cm^2`

Now calculate the difference.

`169-100=69`

Divide it by the original number (100) and multiply by 100

`(69)/(100)*100=69`

This is the increase.