## What’s the equator? Geography and the Earth

This globe shows the equator running around the widest part of the Earth. Where is the equator? The equator is an imaginary line running around the widest part of the Earth, [...]

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08, 2017

This globe shows the equator running around the widest part of the Earth. Where is the equator? The equator is an imaginary line running around the widest part of the Earth, [...]

29
07, 2017

What is pi? The geometry of a circle What is pi? Pi is a number that is just a little bigger than 3.14. It is the number you get if you divide [...]

29
07, 2017

The geometry of a circle The diameter of a circle is the distance across the circle at the widest part of the circle. The diameter is always equal to twice the radius of the [...]

28
07, 2017

The geometry of a circle, with circumference labelled What is the circumference? The circumference of a circle is the distance all the way around the circle. It's the same as the perimeter, but [...]

28
07, 2017

A circle is the set of points on a plane that are all the same distance away from a center point. A circle is the set of points on a plane that are all [...]

28
07, 2017

The geometry of a circle The area of a circle is the flat surface inside its circumference. The area is always equal to the radius squared, multiplied by π (pi). Here's a proof that [...]