# Curve facts for kids

A **curve** is a line that turns or bends. A curved line is never straight, and a curved surface is a surface that is never flat. Some curves can be drawn on paper, but some curves, like a helix, can only be seen in 3-D. A circle is a curve that can be described with the formula *x*^{2} + *y*^{2} = *r*^{2}. *x* and *y* are used as in a Cartesian coordinate system, and *r* is the radius of the circle (distance from the center to the outside). Many other curves can also be described with a formula like that.

## Related pages

## Images for kids

## See also

In Spanish: Curva para niños

Black History Month on Kiddle

Famous African-American Athletes:

Tommie Smith |

Simone Manuel |

Shani Davis |

Simone Biles |

Alice Coachman |

All content from Kiddle encyclopedia articles (including the article images and facts) can be freely used under Attribution-ShareAlike license, unless stated otherwise. Cite this article:

Curve Facts for Kids. *Kiddle Encyclopedia.*