Im trying to use an equation on this page
http://en.wikipedia.org/wiki/Bicycle_and_motorcycle_dynamics
The angle of lean, $\theta$, can easily be calculated using the laws of circular motion
$$ \theta = \arctan\left(\frac{v^2}{gr}\right)$$
where $v$ is the forward speed, $r$ is the radius of the turn and $g$ is the acceleration of gravity. For example, a bike in a 10 m radius steady-state turn at 10 m/s must be at an angle of 45.6°.
If enter the above example values into the equation a get a value of 89.4 not 45.6. What am I doing wrong?
$$ 89.4 = \arctan\left(\frac{10^2}{9.81 \cdot 10}\right)$$
Cheers