A Mobius Strip is an amusing three-dimensional object whose surface has only one side. Huh? Well, most objects you can imagine have a surface with two sides. For example, an ordinary piece of paper ... Continue reading
The cone is another three-dimensional shape based on the circle. You could think of it as the cross between a circle and a right triangle. Its properties will have features of both shapes, and this ... Continue reading
Eratosthenes (c. 276 – 194 BC) was born more than 2200 years ago in the Greek city of Cyrene, now a city in the North African country of Libya. (The Greek Empire surrounded much of the Mediterranean ... Continue reading
A circle is what you get if you take a straight line and bend it around so that its ends touch. You can demonstrate this by taking a piece of stiff wire and doing just that: bring the ends of the wire ... Continue reading
