Answer:
s = 6 cm
Step-by-step explanation:
The area (A) of an equilateral triangle is calculated as
A = [tex]\frac{s^2\sqrt{3} }{4}[/tex] ( s is the length of side )
Here A = 9[tex]\sqrt{3}[/tex] , thus
[tex]\frac{s^2\sqrt{3} }{4}[/tex] = 9[tex]\sqrt{3}[/tex] ( multiply both sides by 4 to clear the fraction )
s²[tex]\sqrt{3}[/tex] = 36[tex]\sqrt{3}[/tex] ( divide both sides by [tex]\sqrt{3}[/tex] )
s² = 36 ( take the square root of both sides )
s = [tex]\sqrt{36}[/tex] = 6
