Find the area of an equilateral triangle that has a perimeter of 21 inches. Round the answer to one decimal place.
21.2 sq inches.
the answer is 32
18 inches and it is an equilateral triangle
The perimeter is the sum of all sides. An equilateral triangle has three sides of equal length. So if one side is 5 inches, and we have three of these, we get a perimeter of 15 inches.
It is: 3*9 = 27 inches