Trig. So hard.

Question

Find the area of the following triangle a=43 inch b=53 inch c=72 inch

Answer 1

Hi!  The trick is to use Heron's Formula.  If s = the semiperimeter (e.g. 1/2(a+b+c) where the sides are a, b, and c), then the area is given by A = sq.rt. of [s(s-a)(s-b)(s-c)].

 

In your case, s = 1/2 * (43+53+72) , so s = 84.

 

Area = sq.rt. of [84*(84-43)*(84-53)*(84-72)] = 1,281,168 sq. in.

 

If we're able to talk in person, I'm happy to walk you through my thought process -- what tipped me off that Heron's formula was the way to go! -- as well as show you other ways to solve the problem.  :-)

 

Hope that helps!

Catherine