​Each side of an equilateral triangle is 6 cm long. What is its area (in cm²)?

Correct option is A

​Given:
Side of equilateral triangle = 6 cm.

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

where a is the side

Solution: 

Putting the values in the formula;

​$$\text{Area} = \frac{\sqrt{3}}{4} \times 6^2 = 9\sqrt{3}$$ cm² 

Thus, the area of the equilateral triangle is $$9\sqrt3 \ cm^2$$​​