A circle is a shape where every point at its edge is the same distance from the centre. A circular shape or object is one that is in the form of a circle. How many of these circular objects can you ...

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 ...

You’re likely familiar with Pi Day, perhaps the most popular of geeky holidays. Hooray. But I’m here to tell you that Pi Day is wrong — or rather, the entire idea of pi as a mathematical concept is ...