We can use somethng called "Pick's Theorem"
Lattice point = a point defined by the intersection of grid lines
Interior lattice points = 17
Boundary lattice points = 8
Area = interior lattice points + boundary lattice points / 2 - 1 =
17 + 8/2 - 1 =
14 + 4 - 1 =
20
+0 
