Centre Centre: Each point of a circle is at equal distance from a fixed point. The fixed point is called the centre of the circle. Centre is in the interior part of the circle but centre is not a part of a circle.
Radius The distance from the centre to any point on the circle is called the radius of the circle.
Diameter A line segment passing through the centre and whose end points are on the circle is called the diameter of the circle.
Chord A line segment whose end points are on circle is called a chord. Diameter is a longest chord of the circle.
Circumference The length of a circle is called a circumference.
Assessment Fill in the blanks 1. -------- is not a part of a circle. 2. Centre lies in the -------- part of a circle. 3. Diameter of a circle is ----------- of the radius. 4. ------------ of the circle is half of its diameter.