Sp² Hybridization:

 In sp² hybridization, the s orbital is merged along with two of the 2p orbitals (for example 2p_x and 2p_z) to provide three sp² hybridized orbitals of equivalent energy. The remaining 2p_y orbital is not affected. The energy of every hybridized orbital is greater as compared to the original s orbital but less than the original p orbitals. The remaining 2p orbital (in this matter the 2p_y orbital) remains at the original energy level of it.

Diagram: sp² Hybridization.