It depends on the phase and the temperature
Solid AlCl3 has each aluminium is 6 coordinate, surrounded by 6 chlorine atoms in an octahedral formation. The best description here is a ionic bonding. Interestingly just below melt temperature the conductivity rises indicating free ions.
AlCl3 in the melt is found as dimer Al2Cl6 with four coordinate aluminium. Two chlorines bridging the aluminium atoms. In this aluminium achieves its octet and the bond angles are in line with VSEPR theory.
At high temperature the dimers dissociate to monomeric AlCl3 which is trigonal planar, following VSEPR theory.
trigonal planar
Trigonal Planar
Trigonal Pyramidal. It is not trigonal planar because there is one lone pair around the central atom, just like the shape of ammonia.
Trigonal Planar
Trigonal planar.
trigonal planar
Trigonal Planar
CO32- is trigonal planar, bond angles are 1200
Formaldehyde has a nonpolar trigonal planar molecule.
Bromine gas is linear because there is only two atoms involved in the molecule.
Not linear.
Sulfur tetraoxide is a trigonal planar. There is the sulfur in the middle and three oxygen that surrounds it with all of them a double bond linking them to the sulfur.
Trigonal Planar
nh3
nh3
Trigonal planar
Trigonal Pyramidal. It is not trigonal planar because there is one lone pair around the central atom, just like the shape of ammonia.