Definition: The part of a circle enclosed by two
radii of a circle and their
intercepted arc.
A pie-shaped part of a circle.

Try this Drag one of the orange dots that define the endpoints of the blue arc.
The sector of the circle is shown in yellow.

As you can see from the figure above, a sector is a pie-shaped part of a circle. It has two straight sides (the two radius lines), the curved edge defined by the arc, and touches the center of the circle.

Radius | The radius of the circle of which the sector is a part | |

Central Angle | The angle subtended by the sector to the center of the circle. See Central Angle of an Arc for more. | |

Arc length | The length around the curved arc that defines the sector (shown in red here). For more on this see Arc length definition. |

- Circle definition
- Radius of a circle
- Diameter of a circle
- Circumference of a circle
- Parts of a circle (diagram)
- Semicircle definition
- Tangent
- Secant
- Chord
- Intersecting chords theorem
- Intersecting secant lengths theorem
- Intersecting secant angles theorem
- Area of a circle
- Concentric circles
- Annulus
- Area of an annulus
- Sector of a circle
- Area of a circle sector
- Segment of a circle
- Area of a circle segment (given central angle)
- Area of a circle segment (given segment height)

- Basic Equation of a Circle (Center at origin)
- General Equation of a Circle (Center anywhere)
- Parametric Equation of a Circle

- Arc
- Arc length
- Arc angle measure
- Adjacent arcs
- Major/minor arcs
- Intercepted Arc
- Sector of a circle
- Radius of an arc or segment, given height/width
- Sagitta - height of an arc or segment

(C) 2011 Copyright Math Open Reference.

All rights reserved

All rights reserved