File:Spherical and polar triangle altitude.svg - Wikimedia Commons
Spherical coordinate system with polar angle ϑ and azimuthal angle φ.:... | Download Scientific Diagram
Spherical coordinates system (spherical polar coordinates) Newtonian Mechanics
How to find velocity in spherical coordinates - Quora
The spherical polar coordinates (r, \theta , \phi) are defined in the figure below. Derive the expressions given there for x,y and z in terms of (r, \theta, \phi). Find corresponding expressions