In fig (i) parallelogram ABCD and triangle AEF are between the same parallels AB and CD, but do not share the common base.
In fig (ii) parallelogram ABCD and triangle AEB are sharing the common base AB but not lying between the same parallels.
In fig (iii) parallelogram ABCD and parallelogram ABEF are on a common base AB and between the same parallels AB and DE.
In fig (iv) parallelogram ABCD and parallelogram ABEF are sharing a common base AB, but not lying between the same parallels.