PX262 - F2b - degeneracy

if two or more sides of the potential well are of the same length, eg: $a = b$ , the energies of the states will be: $E_{n_{1} n_{2} n_{3}} = \frac{ℏ^{2} π^{2}}{8 M} (\frac{n_{1}^{2} + n_{2}^{2}}{a^{2}} + \frac{n_{3}^{2}}{c^{2}})$
in such cases, there will be several states with the same energy, ie. it is a degenerate system
eg: $(n_{1} = 1, n_{2} = 2)$ and $(n_{1} = 2, n_{2} = 1)$ have the same energies but different corresponding eigenfunctions
3D systems exhibit such behaviour regularly