Ever wonder how fast you're spinning around the imaginary rod connecting the North and South Poles? Wonder no more. By finding your location on this map and searching for where your line of latitude intersects with the bold, black curve, you can determine the speed at which you're currently zipping around Earth's axis.
In high school, you probably learned that trigonometric functions – like sine, cosine and tangent –can be derived, geometrically, from a circle (hence why trig functions are also known as "circular" functions). But what happens if you use a square to derive these functions, instead? Or a triangle? Or a heart?