Question

Find the area of a triangle with sides lengths 17, 18, and 21.4 units. Round the answer to the nearest hundredth.

Answer 1

To calculate for the area of the triangle given all its side, use the Heron's formula which is, 
 
                            A = sqrt ((s)(s - a)(s - b)(s - c))

where A is the area. a, b, and c are the measure of the sides and s the semi - perimeter or half of the perimeter.

With the given above, s = (17 + 18 + 21.4) / 2 = 28.2

Substituting the known dimensions to the Heron's formula,
          
          A = sqrt ((28.2)(28.2 - 17)(28.2 - 18)(28.2 - 21.4)) = 148 units^3

Thus, the area of the triangle is 148 units^3.