geometry Geometry (; ) is, with arithmetic, one of the oldest branches of mathematics. It is concerned with properties of space such as the distance, shape, size, and relative position of figures. A mathematician who works in the field of geometry is c ...

, a glissette is a

curve In mathematics, a curve (also called a curved line in older texts) is an object similar to a line (geometry), line, but that does not have to be Linearity, straight. Intuitively, a curve may be thought of as the trace left by a moving point (ge ...

determined by either the locus of any point, or the

envelope An envelope is a common packaging item, usually made of thin, flat material. It is designed to contain a flat object, such as a letter or card. Traditional envelopes are made from sheets of paper cut to one of three shapes: a rhombus, a shor ...

of any line or curve, that is attached to a curve that slides against or along two other fixed curves.

Examples

Ellipse

A basic example is that of a line segment of which the endpoints slide along two perpendicular lines. The glissette of any point on the line forms an

ellipse In mathematics, an ellipse is a plane curve surrounding two focus (geometry), focal points, such that for all points on the curve, the sum of the two distances to the focal points is a constant. It generalizes a circle, which is the special ty ...

Astroid

Similarly, the envelope glissette of the line segment in the example above is an astroid. Astroid_glissette

Conchoid

Any conchoid may be regarded as a glissette, with a line and one of its points sliding along a given line and fixed point. Nicomedes

References

{{Reflist

External links

Glissette at Wolfram Mathworld
Curves