Answer:
71.4
Step-by-step explanation:
For this, we will use Heron's Formula, or
[tex]\sqrt{p(p-a)(p-b)(p-c)}[/tex],
with p as the perimeter divided by 2, and a, b, and c are the side lengths.
Plugging our values in, (11.6+20+13)/2 = 22.3 = p, and
[tex]\sqrt{p(p-a)(p-b)(p-c)}[/tex] = [tex]\sqrt{5103.8679} =71.4[/tex] rounded to the nearest tenth
