What hybridization is required for central atoms that have a tetrahedral arrangement of electron pairs? A trigonal

Question:

What hybridization is required for central atoms that have a tetrahedral arrangement of electron pairs? A trigonal planar arrangement of electron pairs? A linear arrangement of electron pairs? How many unhybridized π atomic orbitals are present when a central atom exhibits tetrahedral geometry? Trigonal planar geometry? Linear geometry? What are the unhybridized π atomic orbitals used for?