French curve
Sign in to savetemplate made from metal, wood or plastic composed of many different curves; used in manual drafting to draw smooth curves of varying radii
~1 min read
Encyclopedic overview
(Learn how and when to remove this message)
A set of the three most common French curves, also known as a Burmester set. The bottom object is most commonly used for hyperbolas; the smaller one above it is suited for ellipses. The large one is used mostly for parabolas.
Excerpted from Wikipedia’s “French curve” article, available under the CC BY-SA 4.0 licence.