Opposite sides of a parallelogram are congruent and parallel.

Since the vertex C is b units long from y-axis, the x-coordinate of E is b.

Since the vertex G is  units long from x-axis, the y-coordinate of E is .

The coordinates of E are .

Since the vertex G is  units long from y-axis, the x-coordinate of A is .

Since the vertex C is b units long from x-axis, the y-coordinate of A is b.

The coordinats of A are .

The coordinats of A are .

The coordinates of E are .