The rotational kinetic energy of a body is $K_{rot}$ and its moment of inertia is $I$. The angular momentum of body is

Rotational kinetic energy of a body, 

$K_{rot}=\frac{1}{2}I{\omega }^2$ 

or, $I{\omega }^2=2K_{rot}$ or $\omega =\sqrt{\frac{2K_{rot}}{I}} ....\left(i\right)$ 

Angular momentum of a body $L=I\omega$ 

or, $L=I\sqrt{\frac{2K_{rot}}{I}}=\sqrt{2I{K}_{rot}} \left[From \left(i\right)\right]$