Included side
From Latin: includere "to shut in, enclose"
Definition: The common leg of two angles.

Usually found in triangles and other polygons, the included side is one that links two angles together. Think of it as being 'included' between two angles.

See also Included angles

While you are here..

... I have a small favor to ask. Over the years we have used advertising to support the site so it can remain free for everyone. However, advertising revenue is falling and I have always hated the ads. So, would you go to Patreon and become a patron of the site? When we reach the goal I will remove all advertising from the site.

It only takes a minute and any amount would be greatly appreciated. Thank you for considering it!   – John Page

Become a patron of the site at

Other line topics