Answer:1. VSEPR theory
2. SP2
3. Sp3
Explanation: VSEPR means valence shell electron pair Repulsion. The theory states that, it is the nature of the valence electrons in a molecule that determines their shape. Lone pair of electrons create higher level of repulsion. The higher the level of lone pair present, Te higher Te distortion in shape which leads to lowering of bond angle.
Hybridization usually involves the 2s and 2p orbitals.
Hybrid orbital for boron is sp2 and for carbon is sp3