In geometry, an apex is a descriptive label for a visual singular highest or most distant point or vertex in an isosceles triangle, pyramid or cone, usually contrasting with the opposite side called the base. Image File history File links Pyramid. ... Calabi-Yau manifold Geometry (Greek γεωμετρία; geo = earth, metria = measure) is a part of mathematics concerned with questions of size, shape, and relative position of figures and with properties of space. ... Look up vertex in Wiktionary, the free dictionary. ... A triangle is one of the basic shapes of geometry: a polygon with three vertices and three sides which are straight line segments. ... This article is about the polyhedron pyramid (a 3-dimensional shape); for other versions including architectural Pyramids, see Pyramid (disambiguation). ... This article is about the geometric object, for other uses see Cone. ...