maths

                                                      Parts of circle The fixed point is called the centre of circle. The constant distance between the fixed point and the moving point is called the radius of the circle. The radius is a line segment with one end point at the centre and the other end on the circle.  It is denoted by 'r'. A line segment joining any two points on the circle is called a chord. Diameter is a chord passing through the centre of the circle.  It is denoted by 'd'.