Answer:
The thing is I don't know if like is will put fractions or decimals so I guess try both if u can if not I would go for decimals first because that is more probable.
Midpoint of some points
AB midpoint = -1,1.5
BC midpoint = -2.5,2
CA midpoint = -2.5,1.5
Midpoint of DE = -3,0
Midpoint of FG = 3,-1
Sorry that it took some time