Spherical angle
Encyclopedia
A spherical angle is a particular dihedral angle
; it is the angle between two intersecting arcs on a sphere
, and is measured by the angle between the planes containing the arcs (which would naturally also contain the centre of the sphere).
Dihedral angle
In geometry, a dihedral or torsion angle is the angle between two planes.The dihedral angle of two planes can be seen by looking at the planes "edge on", i.e., along their line of intersection...
; it is the angle between two intersecting arcs on a sphere
Sphere
A sphere is a perfectly round geometrical object in three-dimensional space, such as the shape of a round ball. Like a circle in two dimensions, a perfect sphere is completely symmetrical around its center, with all points on the surface lying the same distance r from the center point...
, and is measured by the angle between the planes containing the arcs (which would naturally also contain the centre of the sphere).