Scientific American presents Math Dude by Quick & Dirty Tips. Scientific American and Quick & Dirty Tips are both Macmillan companies. Throughout history, circles have symbolized many things: unity, ...

Though the exact length of a "stadia" is unknown, his measurement is thought to be accurate to within one percent of the ...

Imagine a piece of string wrapped around the Earth's equator - that's about 40,000km. How much MORE string would you need for it to sit 15cm above the ground, all the way around? The important thing ...

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 ...

A circle is a two-dimensional figure that is defined by a set of points that are all the same distance from a given point, known as the center. It is considered a type of line with a collection of ...

In the mid-20th century, we began launching satellites into space that would help us determine the exact circumference of the Earth: 40,030 km. But over 2000 years earlier, a man in Ancient Greece ...