If each side of a triangle is doubled, then find percentage increase in its area.
Let the sides of triangle are a, b, c
When a, b and c are the sides of triangle and s is the semi-perimeter, then its area is given by:
A = 
where 
[Heron’s Formula]
A’ = 
where 
[Heron’s Formula]
When each side of triangle is doubled
= 
= 2
A’ = 
A’ = 
= 4
= 4A
Increase in area = 4A-A = 3A
Percentage increase in area = 
= 
= 300%
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