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%

Step-by-step 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

$\frac{69}{100}*100=69$

This is the increase.