Question

if the height of an equilateral triangle is 8cm calculate its area

Answer 1

area=1/2 x base x height
        =1/2 x 8 x 8  (since it is a equilateral triangle)
area=32cm^2

Answer 2

Height = 8 cm

$\frac{ \sqrt{3} }{2} a \: = 8$
squaring

$\frac{3}{4} {a}^{2} = 64$
Area of the equilateral triangle

$\frac{ \sqrt{3} }{4} {a}^{2}$
$= \frac{64}{ \sqrt{3} } {cm}^{2}$