Jomon Three-Dimensional Angle

Abstract

A three-dimensional angle is a geometric figure which is formed by line segment and line segment and line segment at point . The angle between line segment and line segment is equal to the angle between line segment and line segment . The angle between line segment and line segment is equal to the angle between line segment and line segment . is the central axis. The angle measure is expressed by the degree of opening of line segment from the central axis. The range of the angle measure is greater than or equal to zero and less than or equal to one.