Wolfram Math World: Apothem

MathWorld provides a huge mathematics encyclopedia detailing the concepts of geometry, algebra, calculus, discrete math, number theory, and other math topics--complete with formulas, diagrams, examples, and references for thorough...

This webpage thoroughly discusses the math of spheres. Includes the equation for a sphere in Cartesian and spherical coordinates as well as parametrically. Surface Area, volume, and curvature are addressed at this extensive site.

This math site gives the formula for taking the dot product of two vectors, gives properties of dot products, (commutative, associative, and distributive), how to find the derivative of a dot product. This site has links to several other...

This MathWorld tutorial provides detailed overviews of the concepts and theorems associated with geometry. Most of the Math World sites are extensive and some require higher math knowledge to understand, links to terms and topics are...

Math World explains the Golden Ratio, gives the formula for finding the irrational number, and expresses this value as an infinite series. Also defines and represents the Ratio geometrically, its relationship to the Fibonacci numbers,...

At this site from Math World you can find out various normal vector formulas, including normal vectors of planes, surfaces, tangent vectors, and three dimensional surfaces. This site also explains how the unit normal vector is derived.

This Math World site explains how the hyperboloid is created from a hyperbola, illustrated with graphs. The site then goes into detail giving the parametric and cartesian equations for a one sheeted hyperboloid and then the two sheeted...

This math tutorial site covers set theory, axioms, category theory, logic, mathematical problems, and point-set topology.

This math site explains what it means for a number to be irrational and names various persons who have proven the irrationality of some numbers, the site also gives several numbers who are thought to be irrational yet have not been...

This World of Mathematics site by Eric Weisstein explains the term "Standard deviation." Provides step-by-step help, examples, and charts.