Answer: 118.2977 sq. m.
Step-by-step explanation:
Step 1: Calculate "s" (half of the triangles perimeter):
s = a+b+c / 2
s = (13 + 18.2 + 22.3) / 2
s = 26.75
Step 2: Then calculate the Area:
Herons formula
A = √( s(s-a)(s-b)(s-c) )
A = √(26.75 (26.75 - 13)(26.75-18.2)(26.75-22.3)
A = (3√9951535) /80
A = 118.2977 sq. m.
