Hybridization was introduced to explained the molecular structure when the valence bond theory fail to correctly predict them, it is experimental observation observed that bond angle in an organic compound are close to 109 degrees 120 degree or 180 degree according to valence shell electron pair repulsion theory, (VSERP) theory, electron pair repel each other and the bond and lone pair around the central atoms are generally separated by the largest possible angles.
The sp² can explain the triagonal planner structure of molecules in it the 2s obitals and two of the 2p orbitals hybridized to form sp orbitals. Each consist of 67% p and 33% s character. The frontal lobe align themselves in the triangular plant structure pointing to the corner of triangle in order to minimise election repulsion and to improve overlap. The remaining p orbital remains unchanged and is perpendicular to the plane of the three sp² orbitals.