Answer:
When rotating a point 90 degrees counterclockwise about the origin our point A (x,y) becomes A' (-y,x). In other words, switch x and y and make y negative.
So for this, each point would become as follows:
J (1,-3) becomes J' (3,1)
K (5,0) becomes K' (0,5)
L (8,-4) becomes L' (4, 8)
M (4,-7) becomes M' (7,4)
