# How do you use Heron's formula to determine the area of a triangle with sides of that are 25, 29, and 31 units in length?

##### 1 Answer

Feb 25, 2016

#### Explanation:

The semi-perimeter,

#s = frac{a+b+c}{2} #

#= frac{25+29+31}{2}#

#= 85/2#

Now Heron's formula states that the area of the triangle is

#A = sqrt{s(s-a)(s-b)(s-c)}#

#= sqrt{85/2(85/2-25)(85/2-29)(85/2-31)}#

#= {15sqrt8211}/4#