hypocycloid

[ hahy-puh-sahy-kloid ]

noun

, Geometry.

1. a curve generated by the motion of a point on the circumference of a circle that rolls internally, without slipping, on a given circle.

hypocycloid

/ ˌhaɪpəˈsaɪklɔɪd /

noun

1. a curve described by a point on the circumference of a circle as the circle rolls around the inside of a fixed coplanar circle Compare epicycloid cycloid

hypocycloid

/ hī′pō-sī′kloid′ /

1. The curve described by a point on the circumference of a circle as the circle rolls on the inside of the circumference of a second, fixed circle.

Derived Forms

• ˌhypocyˈcloidal, adjective

Other Words From

• hypo·cy·cloidal adjective

Word History and Origins

Origin of hypocycloid¹

First recorded in 1835–45; hypo- + cycloid

Example Sentences

A hypocycloid with 3 cusps, also called a deltoid, is made by rolling a circle inside a circle with a radius three times as large.

From Scientific American

But the minimum of friction is attained when the two flanks for the tooth are drawn into one common hypocycloid, as in Fig.

From Project Gutenberg

The curve generated by rolling on the concave side is called a 'hypocycloid'.

From Project Gutenberg

A quick check shows why the 3-point hypocycloid works and the other fails: a line dropped from the very top of the hypocycloid will across horizontally at the bottom curve.

From New York Times

If the radius of the rolling circle be one-half of the fixed circle, the hypocycloid becomes a diameter of this circle; this may be confirmed from the equation to the hypocycloid.

From Project Gutenberg