This is what I put "I used the m=y2-y1/ x2-x1 to solve for the slopes (-1,3) and (1,2) has a slope of -1/2. (1,2) and (-3,-1) has a slope of 3/4. (-1,3) and (-3,-1) has a slope of 2. I plotted this on a graph and came to the conclusion that is was an acute isosceles triangle."