How to find the area of a equilateral triangle that has a perimeter of 21?

First, we have to find the length of each side of triangle. Equilateral triangle means 3 sides r in same length, so each side will be 21 : 3 = 7

Now we need to calculate the height of the triangle. We can do this by Pythagoras theorem

Let the height be h

(7/2) ^2 + x^2 = 7^2

The area should be 6.0621778265

Or u can say 6.06 corrected to 3 sig fig