If the area of an equilateral triangle i...

If the area of an equilateral triangle is `81 sqrt(3) cm^(2)`, find its height.

A

`9 sqrt(3)` cm

B

`6 sqrt(3)` cm

C

`18 sqrt(3)` cm

D

9 cm

Verified by Experts

The correct Answer is:

A

`(sqrt(3))/(4)a^(2)=81 sqrt(3)cm^(2) rArr a^(2) = (81 xx 4)cm^(2) rArr a = 18 cm`.
Height `=(sqrt(3)a)/(2)=((sqrt(3))/(2)xx 18)cm = 9 sqrt(3) cm`.

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