9514 1404 393
Answer:
3.6 cm²
Explanation:
Heron's formula is usually used for calculating triangle area from side lengths.
The semiperimeter is ...
s = (7.2 +1.2 +6.6)/2 = 7.5
Then the area is ...
A = √(s(s -f)(s -g)(s -h)) = √(7.5(0.3)(6.3)(0.9)) = √12.7575
A ≈ 3.57176 cm²
The area of ΔFGH is about 3.6 square centimeters.