If the length of

The area of an equilateral triangle of side a =

A=

Here A₁ =

Now, if the side is tripled, the side it becomes 3a

the new area is

A=

A=

A =

⇒ A = 27 A₁

The increase in percentage of the area of the equilateral triangle

=

=

= 26 × 100

= 2600

Hence the % increase in area of equilateral triangle is 2600 %