Learn About Pi



History of Pi


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The number pi is extremely useful when solving geometry problems involving circles. Here are some examples:

The area of a circle.

A = πr2

Where ‘r’ is the radius (distance from the center to the edge of the circle). Also, this formula is the origin of the joke “Pies aren’t square, they’re round!”

The volume of a cylinder.

V = πr2h

To find the volume of a rectangular prism, you calculate length × width × height. In that case, length × width is the area of one side (the base), which is then multiplied by the height of the prism. Similarly, to find the volume of a cylinder, you calculate the area of the base (the area of the circle), then multiply that by the height (h) of the cylinder.