Answer:
47.906 square units
Step-by-step explanation:
The lengths of the sides are ...
3+5 = 8
3+9 = 12
5+9 = 14
The semiperimeter (s) is ...
s = (8 + 12 + 14)/2 = 17
So, by Heron's formula, the area is ...
a = √(s(s -a)(s -b)(s -c)) = √(17(17-8)(17-12)(17-14)) = √(17·9·5·3)
a = √2295 ≈ 47.906
The area is about 47.906 square units.
