All Classical and Elementary Geometry

Branches that study the shapes of the plane and of ordinary space using the methods that were developed first. An entry belongs here when its cited source describes the geometry of points, lines, triangles and circles, the measurement of angles, or the trigonometric functions that relate sides and angles. It does not belong here when the branch deals with curved spaces, with geometry that rejects the parallel postulate, or with finite configurations studied combinatorially. The group is the entry point to geometry and holds the general survey of the subject.