A farmer is mapping out one of his fields and is placing markers to section off areas to use for different crops. He has placed marker 1 at the point (2, 1), marker 2 at the point (-3, 1), and marker 3 at the point (2, 5). Each grid on the map is a square acre.

If the farmer wants to make a triangular field for soybeans between the markers, what will the area of the field be?