Rolling a Coin around a Coin

Requires a Wolfram Notebook System
Interact on desktop, mobile and cloud with the free Wolfram Player or other Wolfram Language products.
The red circle rolls on the outside of the black circle of radius 1. (The blue point shows how it rolls.) An invisible point at distance from the center of the black circle is attached to the red circle, tracing out a path as the red circle rolls; such curves are called epitrochoids.
Contributed by: Daniel Lichtblau (March 2011)
Additional contributions by: Jacqueline D. Wandzura
Open content licensed under CC BY-NC-SA
Snapshots
Details
detailSectionParagraphPermanent Citation
"Rolling a Coin around a Coin"
http://demonstrations.wolfram.com/RollingACoinAroundACoin/
Wolfram Demonstrations Project
Published: March 7 2011