The angle from the origin to the point (2, 1) isn't 22.5 degrees – it's arctan(1/2) = 26.6 deg. In fact, the slope of the point you want should be sqrt(2) – 1 =

The angle from the origin to the point (2, 1) isn't 22.5 degrees – it's arctan(1/2) = 26.6 deg. In fact, the slope of the point you want should be sqrt(2) – 1 = 0.414, not 0.5.