Question

How do you use Heron's formula to find the area of a triangle with sides of lengths `9`, `4`, and `9`?

Answer 1

Let a,b,c be the lengths of the sides of a triangle. The area is given by:
`Area = sqrt[p(p-a)(p-b)(p-c) ]`
where p is half the perimeter, or `p=1/2*(a+b+c)`

Now replace values of `a=9,b=4,c=9` to find that

`Area~~17.55`