circle

A circle is a two-dimensional shape formed by a full curve equidistant from the centre of the circle.

A circle has only one side, it has no vertices.

The formula for the circumference of a circle (the length of the curved line) is:

    Circumference = \pi \times Diameter
                                   C=\pi d

or

    Circumference = 2 \times \pi \times Radiws

                                   C=2\pi r

The formula for the area of a circle is:

                            Area = \pi \times r^{2}

                                   A= \pi r^{2}