Find the percentage increase in the area of a triangle if its each side is doubled.

Explanation

1) area of triangle is `A_1=sqrt(s(s-a)(s-b)(s-c)`

2) If each side is doubled

`A_2=sqrt(2s(2s-2a)(2s-2a)(2s-2c)`

`=4sqrt(s(s-a)(s-b)(s-c)`

`A_2=4A_1`

Percentage change`=(A_2-A_1)/A_1*100`

`=(3A_1)/A_1*100`

`=300%`.