It's not a rectangle, and it's certainly not contained only in the first and second quadrants.
Try plotting the points again.
If you make further efforts on your own and need help, mouse over this box.

Show[ListPlot[{{5, 5}, {1, -3}, {-4, 2}, {-2, 6}},
PlotRange -> {{-7, 7}, {-7, 7}}, AspectRatio -> 1,
PlotStyle -> {Red, PointSize[0.02]}, LabelStyle -> Directive[12]],
Graphics[Text[Style["5+5[ImaginaryI]", Directive[18]], {5, 4.1}]],
Graphics[Text[Style["1-3[ImaginaryI]", Directive[18]], {2.2, -3}]],
Graphics[Text[Style["-4+2[ImaginaryI]", Directive[18]], {-4, 2.7}]],
Graphics[Text[Style["-2+6[ImaginaryI]", Directive[18]], {-3.4, 6}]]]