Question

Find the area of equilateral triangle having each side 2a

Answer 1

Area of equilateral triangle = √3/4*s²
S=2a 
Area = √3/4 *(2a)² 
        =√3/4 *4a²
        = √3a²

Answer 2

Equilateral triangle: the altitude h can be found as below, as the altitude divides the triangle in to two equal parts. The base is divided into two.

h² = side² - (side/2)² = 3/4 side² = 3 a²

h = √3 a

area = 1/2 (2a) √3 a  = √3 a²