Properties of Circles

Definition of a circle

The resulting shape of all points on a plane equidistant from the centre of the circle

Definition of circumference

A closed curve that is the boundary of a round shape

Definition of radius

A straight line connecting the centre of a circle with a point on the circumference of the circle

Formula of diameter

2 × radius

Definition of chord

A line segment connecting any two points on a curve

Definition of arc

A line of curve connecting any two points on the circumference of a circle

Definition of minor arc

Part of the circumference that is less than half of the circle

Definition of major arc

Part of the circumference that is more than half of the circle

Definition of diameter

A straight line connecting two points on a circumference and through the centre of a circle on the circle

Definition of sector

The inside of a circle bounded by two radii and the arc connecting the end points of the two radii