How_To_Be_Good_At_Math

220 GEOMETRY • CIRCLES

Circles

A circle is a 2D shape, made from a curved line that goes

all the way round a point at the centre. Every point on the line

is the same distance from the centre.

Parts of a circle

This drawing shows the most important parts of a circle.

Some of these parts have special names that we don’t

use for other 2D shapes.

Segment

Chord

Circumference

Diameter

Radius

Sector

Arc

Area

Tangent

Centre

The distance from the

centre to any point on a

circle’s circumference is

always the same.

220_221_circles.indd 220 29/02/2016 18:04