Question

an equilateral traingle has side 10cm. find its area

Answer 1

the are of equilateral triangle is given by
$\frac{ \sqrt{3} {a}^{2} }{4} \\ a = side \: of \: the \: triangle = 10 \\ \frac{ (\sqrt{3})100 }{4} \\ 25 \sqrt{3}$

Answer 2

Heya !!

$\text{Side of \triangle = 10 cm}\\\\\text{Area of equilateral triangle = \dfrac{\sqrt{3}}{4} \times (side)^2 }\\\\= \dfrac{\sqrt{3}}{4} \times 10^2 \\\\= \dfrac{\sqrt{3}}{4} \times 10 \times 10 \\\\= \sqrt{3} \times 25 \\\\= 25 \sqrt{3} \: cm^2 or \: 25 \times 1.732 \\\\= \underline{\boxed{\boxed{43.3 \: \: cm^2}}}$

Hope it helps !!