Volume

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The volume of a solid body is the amount of "space" it occupies. Volume has units of length cubed (i.e., cm^3, m^3, in^3, etc.) For example, the volume of a box (cuboid) of length L, width W, and height H is given by

 V=L×W×H.

The volume can also be computed for irregularly-shaped and curved solids such as the cylinder and cone. The volume of a surface of revolution is particularly simple to compute due to its symmetry.

The volume of a region can be computed in the Wolfram Language using Volume[reg].

The following table gives volumes for some common surfaces. Here r denotes the radius, h the height, and A the base area, and, in the case of the torus, R the distance from the torus center to the center of the tube (Beyer 1987).

surfacevolume
cone1/3pir^2h
conical frustum1/3pih(R_1^2+R_2^2+R_1R_2)
cubea^3
cylinderpir^2h
ellipsoid4/3piabc
oblate spheroid4/3pia^2c
prolate spheroid4/3pia^2c
pyramid1/3Ah
pyramidal frustum1/3h(A_1+A_2+sqrt(A_1A_2))
sphere4/3pir^3
spherical cap1/3pih^2(3r-h)
spherical sector2/3pir^2h
spherical segment1/6pih(3a^2+3b^2+h^2)
torus2pi^2Rr^2

Even simple surfaces can display surprisingly counterintuitive properties. For instance, the surface of revolution of y=1/x around the x-axis for x>=1 is called Gabriel's horn, and has finite volume, but infinite surface area.

The generalization of volume to n dimensions for n>=4 is known as content.

For many symmetrical solids, the interesting relationship

 S=(dV)/(dr)

holds between the surface area S, volume V, and inradius r. This relationship can be generalized for an arbitrary convex polytope by defining the harmonic parameter h in place of the inradius r (Fjelstad and Ginchev 2003).

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