## Related pagesThe small affine planes |

- for each line l of .
- for each point p of .
- for each parallel class C of .
- There are exactly n+1 parallel classes in .
- .
- .

There exists a finite affine plane of order n if and only if there is a projective plane of order n. If all projective planes of order n are known, the affine planes of order n are exactly the affine derivatives of these planes. In particular, the isomorphism types of affine planes of order n correspond to orbits of lines under the automorphism groups of projective planes of order n.

In practice, the exact number of ismorphism types of affine planes of order n is only known for a few small values of n.

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