# Naming circle parts

**Naming the parts of a circle**

The definition of a circle is that it is a set of points equidistant from its centre

Circumference – the distance around the outside of the circle

Radius – distance from the centre of the circle to the circumference

Diameter – the distance of the width of the circle though the centre.

**Arcs and sectors**

Arc – is the length which is part of a circumference. Arcs which are shorter than a semicircle is a minor arc and one which is longer than a semi circle is a major arc.

Sector – a part of a circle which is between two radii, an arc and from the centre.