This is a right triangle, so first find the distance between the two legs...
Points where the numbers are the same indicate a point that is on the same axis as the other
(-3, 3) and (-3, 2) have a distance of 1
(-3,2) and (1,2) have a distance of 4
The area formula for a triangle is 1/2bh and in this case 1/2(1)(4) = 2
The area is 2