Q22 of 99 Page 267

If length of each side of an equilateral triangle is doubled, what percent of area will be increased of this triangle?

The area of an equilateral triangle of side a =


A=


Here A1 =


Now, if we double the side it becomes 2a


the new area is


A=


A=


A =


⇒ A = 4A1


The increase in percentage of the area of the equilateral triangle


=


=


= 3 × 100


=300


Hence the % increase in area of equilateral triangle is 300%


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