Question

Find the area of an equilateral triangle whose perimeter is 6a

Answer 1

Perimeter of triangle=3×side
So side= 6a/3
Area=(root3/4)×(6a/3)^2
=(1.732/4)×36a^2/9
=0.433×4a^2
=1.732a^2.

Answer 2

Perimeter of triangle = 3 × side
6a = 3× side
Side = 2a

Area of equilateral triangle = root3/4 × side^2
= root3/4 × 2a^2
=root3/4 × 4a^2
= root3a^2 [4 cancels with 4]

Hope it helps