e/Dunce hat (topology)

Information
has gloss	eng: In topology, the dunce hat is a compact topological space formed by taking a solid triangle and gluing all three sides together, with the orientation of one side reversed. Simply gluing two sides oriented in the same direction would yield a cone much like the layman's dunce cap, but the gluing of the third side results in identifying the base of the cap with a line joining the base to the point.
lexicalization	eng: dunce hat
instance of	(noun) (mathematics) any set of points that satisfy a set of postulates of some kind; "assume that the topological space is finite dimensional" mathematical space, topological space

Media
media:img	Dunce hat animated.gif
media:img	DunceHatSpace.png