Given a line with slope m, if the line is rotated 90∘ clockwise the slope of the resulting figure is − 1/m, how can I determine the slope if the line is rotated 30∘ or 60∘ clockwise. What if its rotated 210 degrees, or 350?

I need to come up with a formula that will factor in the original slope, take/apply the amount I want to rotate, and give me the new slope.

**Edited by GDsnakes, 15 October 2012 - 08:04 AM.**