s = (a + b + c) / 2 or 1/2 of the perimeter of the triangle
A = SquareRoot(s * (s - a) * (s - b) * (s - c))
Enter the length of all three sides. What the unit of measurement is exactly is not important. Click on Calculate and the values for both "s" and the area are returned. You may see all of our other area calculations by going to our Area Calculator.