A planar graph is a graph that can be drawn on a plane (such as a sheet of paper) so that none of its edges cross. Attempt to draw the following, and conjecture which of these tasks are possible and...

A planar graph is a graph that can be drawn on a plane (such as a sheet of paper) so that none of its edges cross. Attempt to draw the following, and conjecture which of these tasks are possible and which are impossible:

(a) Draw a planar clique of size 4.

(b) Draw a planar clique of size 5.