Expected Behavior

Since trigonometric functions are periodic, they should output the same values for angles modulo 360.

Actual Behavior

At very large angles, trigonometric functions (as implemented in the underlying JavaScript VM) accumulate rounding error.

Here's a test case. Mash the spacebar enough and the problem will manifest. Note that these angles are still less than Number.MAX_SAFE_INTEGER. I've confirmed this on Linux Chrome + Firefox and Windows Firefox.