A triangle has sides with lengths: 14, 9, and 12. How do you find the area of the triangle using Heron's formula?

1 Answer
Jan 7, 2016

The area of the triangle is 53.5 square units.

Explanation:

Heron's formula is A=sqrt(s(s-a)(s-b)(s-c)), where A is area, a, b, and c are the sides of the triangle, and s is the semiperimeter, which is half the perimeter.

The formula for the semiperimeter is s=(a+b+c)/2.

Let side a=14, side b=9, and side c=12.

Calculate the semiperimeter.

s=(14+9+12)/2

s=35/2=17.5

Calculate the area of the triangle.

A=sqrt(s(s-a)(s-b)(s-c))

A=sqrt((17.5)(17.5-14)(17.5-9)(17.5-12))

A=53.5 square units

Source: https://www.mathsisfun.com/geometry/herons-formula.html