# How many sides **URL:** \ **Category:** Factual Questions\ **Created:** [April 11, 2004, 10:39pm UTC](https://boards.straightdope.com/t/how-many-sides/239500 "2004-04-11T22:39:34Z")\ **Posts on this page:** 4\ **Page:** 1
**Author:** ![rookie523](https://avatars.discourse-cdn.com/v4/letter/r/71c47a/32.png) [@rookie523](https://boards.straightdope.com/u/rookie523)\ **Post date:** [April 11, 2004, 10:39pm UTC](https://boards.straightdope.com/t/how-many-sides/239500/1 "2004-04-11T22:39:34Z")
How many sides does a semi circle have? 2 or 1? ---
**Author:** ![Joey\_P](https://avatars.discourse-cdn.com/v4/letter/j/919ad9/32.png) [@Joey\_P](https://boards.straightdope.com/u/Joey_P)\ **Post date:** [April 11, 2004, 10:40pm UTC](https://boards.straightdope.com/t/how-many-sides/239500/2 "2004-04-11T22:40:54Z")
Infinite? ---
**Author:** ![ultrafilter](https://avatars.discourse-cdn.com/v4/letter/u/3d9bf3/32.png) [@ultrafilter](https://boards.straightdope.com/u/ultrafilter)\ **Post date:** [April 11, 2004, 11:00pm UTC](https://boards.straightdope.com/t/how-many-sides/239500/3 "2004-04-11T23:00:38Z")
The concept of a side is defined for polygons, and really only makes sense for them. However, if you generalize to graph theory and ask how many edges a semicircle has, it makes sense to say that it has 2, and that a circle has 1. ---
**Author:** ![Thudlow\_Boink](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/thudlow_boink/32/320_2.png) [@Thudlow\_Boink](https://boards.straightdope.com/u/Thudlow_Boink)\ **Post date:** [April 11, 2004, 11:54pm UTC](https://boards.straightdope.com/t/how-many-sides/239500/4 "2004-04-11T23:54:15Z")
Two: an inside and an outside.