Okay, here we have this:
Considering the provided measures, we are going to calculate the area of the triangle, so we obtain the following:
So to calculate the area of the triangle we are going to use Heron's formula. so, we have:

And S is equal to (a+b+c)/2, let's first calculate S and replace with the values in the formula:
S=(47+59+65)/2=171/2=85.5
Replacing:

Finally we obtain that the area of the triangle is approximately equal to 1337.3 ft^2