Methane is tetrahedral but not square planar in nature,prove it.

(N/A) The electronic configuration of carbon in its ground state is $1s^2 2s^2 2p_x^1 2p_y^1$. In the excited state,one electron from the $2s$ orbital is promoted to the $2p_z$ orbital,resulting in $1s^2 2s^1 2p_x^1 2p_y^1 2p_z^1$. These four orbitals undergo $sp^3$ hybridization to form four equivalent $sp^3$ hybrid orbitals directed towards the corners of a regular tetrahedron. If methane were square planar,the $H-C-H$ bond angles would be $90^{\circ}$. However,$X$-ray diffraction studies confirm that the $H-C-H$ bond angle in methane is $109.5^{\circ}$,which is characteristic of a tetrahedral geometry.