Wolfram Research
Wolfram Mathworld: Astroid
Find out how an astroid is related to the ellipse at this math page. This page starts with describing how an astroid may be created easily with two concentric circles with a given ratio, the site then goes into details regarding the...
Wolfram Research
Wolfram Mathworld: Hypocycloid
This clearly explains how a hypocycloid is obtained with great visual aids. Cartesian parametric formulas are given for a general hypocycloid. The last half of the article details how to determine specifics on properties of various...
Wolfram Research
Wolfram Math World: Epicycloid
Shows how to graph them and also derives the polar equations from the parametric equation. The site then defines a few special Epiycloids. Includes a definition, formulas, graphs, video, and links to related topics.
Other
Old Dominion U.: Trochoids, Hypocycloids, & Epicycloids
Has discriptions of Cycloids, Trochoids, Hypocycloids, and Epicycloids are made.
Concord Consortium
The Concord Consortium: Molecular Workbench: Hypocycloid
View a hypocycloid being created in this simulation.
University of St. Andrews (UK)
University of St. Andrews: Hypocycloid
Shows the graph and the parametric cartesian equation. The site also includes links to graphs of related curves and definitions of the associated curves.
Curated OER
University of St Andrews: Hypocycloid
Shows the graph and the parametric cartesian equation. The site also includes links to graphs of related curves and definitions of the associated curves.