Angular Momentum of Electron

[Zywo]

1. The problem statement, all variables and given/known data

The figure shows the wave function of an electron in a rigid box. The electron energy is 12.0 eV. (Figure looks like a sine function and axis have no values, just a red line)


2. Relevant equations

E=(n^2*h^2)/(8mL^2)

3. The attempt at a solution

I don't know how to start this problem with such little information, anyone mind getting me started?
Thanks,
David