Question

If each side of an equilateral triangle is tripled then what is the percentage increase in the area of the triangle

Answer 1

Let the initial side be a units

Area = (√3)a²/4 sq. units

Now, side is tripled,
new side, a' = 3a

New area = (√3)(3a)²/4
                =9×[(√3)a²/4]
                =9×(initial area)

Increase in area = 9×(initial area) - (initial area) = 8 ×(initial area)

% increase = (increase/initial area)×100
                  =[8 ×(initial area)/(initial area)]×100 
                  = 800 %

Answer 2

hope it will help you