geometry

Volume

Volume measures the 3D space occupied by a solid. Units are cubed (cm³, m³). Each shape has its own formula; calculus generalises via integration.

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Volume is the measure of three-dimensional space enclosed by a solid. It is always in cubed units (cm³, m³, in³).

Common formulas:

  • Cube: V=s3V = s^3
  • Rectangular prism: V=lwhV = l \cdot w \cdot h
  • Cylinder: V=πr2hV = \pi r^2 h
  • Sphere: V=43πr3V = \tfrac{4}{3}\pi r^3
  • Cone: V=13πr2hV = \tfrac{1}{3}\pi r^2 h
  • Pyramid: V=13BhV = \tfrac{1}{3} \cdot B \cdot h (BB = base area)

Note the factor of 1/3 for cones and pyramids — they are exactly one-third the volume of the cylinder/prism that contains them with the same base and height.

Calculus generalises volume to arbitrary regions through triple integrals dV\iiint dV and to solids of revolution through the disk/shell methods. The Egyptians knew the pyramid formula thousands of years before calculus existed.

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