The area of a triangle is $9y\, cm^2$. Find the value of y if its area is equal to the area of an equilateral triangle having side 6 cm.

$\sqrt{3}$

We have,

The area of a triangle is $9y\, cm^2$

Area of an equilateral triangle with length of side a = \(\sqrt {3}\) × \(\frac{1}{4}\) × a²

$9y\, cm^2$ = \(\sqrt {3}\) × \(\frac{1}{4}\) × 6²

y = $\sqrt{3}$