trig
posted by sally .
i have to draw a flat unit circle all the way to 4 pi in radians. i can get to 2 pi but i have trouble finding the radians if i went one more time around the unit circle.

what's the trouble? Just trace the circle twice. If you have to label some points along the way, just label each marked point with two values:
pi/2,5pi/2
and so on