to get the x coordinate increment
we subtract x coordinate D from F and would be (-6.5) - (-8.25)=1.75 and then divide it by two to get the increment of one step and that would be 1.75 / 2 =0.875
now we get the y coordinate increment
we subtract y coordinate D from F and would be (-7.5) - (-5.75)=-1.75 and then divide it by two to get the increment of one step and that would be -1.75 / 2 =-0.875
A = (D x coordinate - 1.75,D y coordinate +1.75) A=(-10,-4)
I = (H x coordinate + 0.875,d H coordinate -0.875)
I=(-3.875,-10.125)