Completion requirements

This figure shows an unlabelled copy of the complex plane. The points pi over 2 plus 2 i, 2 i, negative i and negative 3 pi over 2 minus i are all labelled as solid dots. The points 2 i and negative i are on the imaginary axis. The point pi over 2 plus 2 i is in the upper-right quadrant directly to the right of the point 2 i. The point negative 3 pi over 2 minus i is in the lower-right quadrant directly to the left of the point negative i. The points pi over 2, negative pi over 2 and negative 3 pi over 2 are labelled as hollow dots. An unlabelled path is shown as two horizontal line segments and one vertical line segment with marked direction arrow. The first line segment goes from point pi over 2 plus 2 i to point 2 i. The second from 2 i to minus i along the imaginary axis and the third from negative i to negative 3 pi over 2 minus i.