If a = 12, b = 30, and c = 22, find the area of triangle ABC to the nearest tenth.

Question

mertsj · Answer

p=1/2 the perimeter
$$A=\sqrt{p(p-a)(p-b)(p-c)}$$

anonymous · Answer

i don't follow ...

mertsj · Answer

What is it I posted that you don't understand?

anonymous · Answer

I don't follow the p and the a where did you get the formula from. can you explain a little more in-depth please? :)

mertsj · Answer

It's Heron's formula for the area of a triangle when you know 3 sides.  p is half of the perimeter.  Do you know what perimeter is?

anonymous · Answer

Yes I do. but I wasn't expecting all that..but thanks.

mertsj · Answer

So find the perimeter and divide it by 2.  What do you get?

anonymous · Answer

113.137

mertsj · Answer

12+30+22=64 and 64 divided by 2 is 32.  So p = 32.  Plug into the formula.

anonymous · Answer

yeah i got 32*20*2*10 then i did square root..

mertsj · Answer

The directions said to round to the nearest tenth so 113.1