# Radian Rainbows

## Using Tau and rotations in Mathbreakers

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This week for Mathbreakers Labs we met with Michael Hartl, founder of TauDay.com and the Ruby on Rails tutorial, to see how we could represent radians in our game using Tau.

You may already be familiar with Pi, which is approximately 3.14 in decimal form. Pi is obtained by the ratio of the diameter to the circumference of a circle.

Tau is simply 2 pi, or the ratio of the radius to the circumference. Many argue that Tau is a more “natural” number, and this is especially evident when you use Radians. Radians are used with Pi and Tau for rotations, and if you’re more familiar with “degrees”, here’s an easy conversion: One Radian = 57.3°.

Tau (which is nearly equal to 6.28) radians (which are 57.3° each) is a full circle, or 360°. With me so far?

OK, so we can use Tau, and Tau/2, and Tau/4, to represent rotations of a circle. Tau/4 should be one fourth of a circle, or 90 degrees. We built some machines in our world to represent this. Check out the video to see it in action!