A triangle is defined by the points (2,6), (-2,2) & (5,2). Determine the area of the triangle in meters if one unit is equal is equal to one meter.
Graph: 
Solution: 
Using distance formula:
A = [(-2-2)^2 + (2-6)^2 ]^0.5 = 5.657 m
B = [(2-5)^2 + (6-2)2]0.5 = 5 m
C = [(5-(-2))^2 + (2-2)2]0.5 = 7 m
Using Heron’s formula:
Area = [S(S-A)((S-B)(S-C)]^0.5
S = Semi Perimeter = (A+B+C) / 2
S = (5.657 + 5 + 7) / 2 = 8.83 m
Area = [8.83(8.83-5.657)( 8.83-5)( 8.83-7)]^0.5
Area = 14 sq. m. (Answer).