List of formulas in elementary geometry
This is a short list of some common mathematical shapes and figures and the formulas that describe them. Two-dimensional shapes 

Sources:

Three-dimensional shapes 

This is a list of volume formulas of basic shapes:

 Cone – , where  is the base's radius
 Cube – , where  is the side's length;
 Cuboid – , where , , and  are the sides' length;
 Cylinder – , where  is the base's radius and  is the cone's height;
 Ellipsoid – , where , , and  are the semi-major and semi-minor axes' length;
 Sphere – , where  is the radius;
 Parallelepiped – , where , , and  are the sides' length,, and , , and  are angles between the two sides;
 Prism – , where  is the base's area and  is the prism's height;
 Pyramid – , where  is the base's area and  is the pyramid's height;
 Tetrahedron – , where  is the side's length. Sphere 

The basic quantities describing a sphere (meaning a 2-sphere, a 2-dimensional surface inside 3-dimensional space) will be denoted by the following variables
 is the radius,
 is the circumference (the length of any one of its great circles),
 is the surface area,
 is the volume. Surface area:

Volume:

Radius:

Circumference:

See also

References 

Mathematics-related lists