Question

(ii) If the area of an equilateral triangle is 81 root 3 cm^2. Find its side.

Please answer fast and ill mark the brainliest. HURRY PLEASE ILL MARK FIRST ANSWER BRAINLIEST. NO JOKES PLEASE.

Answer 1

Answer:

18 cm

Step-by-step explanation:

Given that:

Triangle is equilateral.

$area \: of \: equilateral \: triangle = 81 \sqrt{3} cm {}^{2}$

Let the side of the triangle be a cm.

We know that,

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

On comparing the given value and the formula we have,

$81 \sqrt{3} = \frac{ \sqrt{3} }{4} {a}^{2}$

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

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

$a = \sqrt{81 \times 4}$

$a = 9 \times 2$

$a = 18 \: cm$

Therefore, the side of the equilateral triangle is 18cm.

Hope it helps you.

Good Luck.