Question

answer this fast please and explain the steps​

Answer 1

$area \: of \: equilateral = \frac{ \sqrt{3} {a}^{2} }{4 } \\ \\ 81 \sqrt{3} cm {}^{2} = \frac{ \sqrt{3} {a}^{2} }{4}$

cutting root3 we get -

$81 \times 4 = {a}^{2}$

$324 = {a}^{2} \\ \\ a = 18$

$h = \frac{ \sqrt{3} a}{2} \\ \\ = \frac{ \sqrt{3} \times 18}{2}$

$= 9 \sqrt{3}$