Circle
Look at the circle. It has no sides.
lt has a centre
Centre is a point from which all points on the circle are at the same distance.
We can draw a line segment from the centre of the circle to any point on the circle. This line is called radius of the circle.
We can draw a line segment from one point of the circle to any other point of the circle, through the centre. This line segment is called diameter of the circle.
Remember that diameter is double of the radius
The distance around the circle is called circumference