This graph is planar. I found it easiest to draw by looking at it with f as the top point and d, a, e, c, b below in a line. This is just a suggestion.

I generally find in problems like this to put the points with most connections on the inside, and put the ones with fewer connections on the outside.

Alumni Liaison

Prof. Math. Ohio State and Associate Dean
Outstanding Alumnus Purdue Math 2008

Jeff McNeal