Answer:
5.5 square units
Step-by-step explanation:
Heron’s formula: sqrt[S(S-A)(S-B)(S-C)
S= semi perimeter
Distance AB = Sqrt: (0- -2)^2 + (0-1)^2 = 2.236
Distance BC = sqrt (0-5)^2 + (0-3)^2 = 5.83
Distance from CA = sqrt (-2-5)^2 + (1-3)^2 = 7.28
Semi perimeter = (2.236+5.83+7.28)/2 = 7.674
Sqrt [(7.674(7.674-2.236)(7.674-5.831)(7.674-7.28)] = 5.497 = 5.5
