Essential revision or learning for a wealth of disciplines like architecture, physics, engineering or design. Understanding the qualities of circles, lines and cones together with a thorough explanation of vectors, provide an excellent foundation to further study.

# The geometry of a circle

In this unit the equation of a circle is found from the co-ordinates of its centre and its radius. There are two different forms of the equation. The unit also covers some examples involving tangents to circles. Video tutorial 40 mins.