Question

Find the area of an equilateral triangle (regular 3-gon) with the given measurement.

9-inch perimeter

A = sq. in.

Answer 1

9/4
`√(3)`

Answer 2

3.89 inches square

Explanation:

We are given with an equilateral triangle and we are required to find its area.

The area of an equilateral triangle is given by the formula

`A=(√(3) )/(4) s^(2)`

Where s is the side of triangle.

Also given that perimeter is 9 inches. This means sum of all equal sides is 9

or

3s=9

that is

x

s=3

Now we put the value of s from here in our formula for Area

`A=(√(3) )/(4) (3)^(2)\\A=(√(3) )/(4) *9\\A=3.89`