List of formulas in elementary geometry

This is a short list of some common mathematical shapes and figures and the formulas that describe them.

Sources:^[1][2][3]

Illustration of the shapes' equation terms

Cube

Cuboid

Prism

Parallelepiped

Pyramids

Tetrahedron

Cone

Cylinder

Sphere

Ellipsoid

This is a list of volume formulas of basic shapes:^{[4]: 405–406}

• Cone – $\frac{1}{3}\pi r^{2}h$, where $r$ is the base's radius
• Cube – $a^3$, where $a$ is the side's length;
• Cuboid – $abc$, where $a$, $b$, and $c$ are the sides' length;
• Cylinder – $\pi r^{2}h$, where $r$ is the base's radius and $h$ is the cone's height;
• Ellipsoid – $\frac{4}{3}\pi abc$, where $a$, $b$, and $c$ are the semi-major and semi-minor axes' length;
• Sphere – $\frac{4}{3}\pi r^3$, where $r$ is the radius;
• Parallelepiped – $abc\sqrt{K}$, where $a$, $b$, and $c$ are the sides' length,$K=1+2\cos (\alpha )\cos (\beta )\cos (\gamma )-{\cos }^2(\alpha )-{\cos }^2(\beta )-{\cos }^2(\gamma )$, and $\alpha$, $\beta$, and $\gamma$ are angles between the two sides;
• Prism – $Bh$, where $B$ is the base's area and $h$ is the prism's height;
• Pyramid – $\frac{1}{3}Bh$, where $B$ is the base's area and $h$ is the pyramid's height;
• Tetrahedron – $\frac{\sqrt{2}}{12}{a}^3$, where $a$ is the side's length.

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

• ${\displaystyle r}$ is the radius,
• ${\displaystyle C=2\pi r}$ is the circumference (the length of any one of its great circles),
• ${\displaystyle S}$ is the surface area,
• ${\displaystyle V}$ is the volume.

Surface area:

$${\displaystyle \begin{array}{rl}S& =4\pi r^2\\ & =\frac{1}{\pi }{C}^2\\ & =\sqrt[3]{\pi (6V{)}^2}\\ \end{array}}$$

Volume:

$${\displaystyle \begin{array}{rl}V& =\frac{4}{3}\pi r^3\\ & =\frac{1}{6{\pi }^2}{C}^3\\ & =\frac{1}{6\sqrt{\pi }}{S}^{3/2}\\ \end{array}}$$

Radius:

$${\displaystyle \begin{array}{rl}r& =\frac{1}{2\pi }C\\ & =\sqrt{\frac{1}{4\pi }S}\\ & =\sqrt[3]{\frac{3}{4\pi }V}\\ \end{array}}$$

Circumference:

$${\displaystyle \begin{array}{rl}C& =2\pi r\\ & =\sqrt{\pi S}\\ & =\sqrt[3]{{\pi }^{2}6V}\\ \end{array}}$$

• Arc length – Distance along a curve
• Physics:List of second moments of area – None
• List of trigonometric identities

0.00 (0 votes) Original source: https://en.wikipedia.org/wiki/List of formulas in elementary geometry. Read more