It is always cool to repeat classic experiments. How many of us know the radius of the Earth because we determined it on our own? I haven't done this, at least not yet. For all my life I have just ...

The radius of a circle or a sphere is the distance between the center and the edge. The radius can be used to calculate a circle's diameter, area and circumference. Likewise, a sphere's volume is ...

When working with circles it is important to recognise and be able to name different parts of the circle. A segment of a circle is an area enclosed by a chord and an arc. What is the name given to a ...