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Pyramidal N-gon

Age 14 to 16 Short Challenge Level:


The base of a pyramid has $n$ edges. In terms of $n$, what is the difference between the number of edges of the pyramid and the number of faces?

If you liked this problem, here is an NRICH task which challenges you to use similar mathematical ideas.

This problem is taken from the UKMT Mathematical Challenges.
You can find more short problems, arranged by curriculum topic, in our short problems collection.