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 (triangle)
trigonal planar
Trigonal Planar
The carbonate ion CO3^2- has a trigonal planar shape. It consists of one carbon atom bonded to three oxygen atoms in a flat, triangular arrangement.
Not linear.
The molecular shape of SeO3 is trigonal planar. It has a central selenium atom bonded to three oxygen atoms, with no lone pairs on the central atom, resulting in a trigonal planar geometry.
nh3
The approximate bond angle for a molecule with a trigonal planar shape is 120 degrees.
nh3
Trigonal planar
The molecular geometry of BF3 is trigonal planar. It has three bond pairs and no lone pairs, resulting in a planar triangular shape. The bond angle between the three fluorine atoms is approximately 120 degrees.
The molecule H2CO, formaldehyde, has a trigonal planar molecular shape with a bond angle of 120 degrees. It is a polar molecule due to the difference in electronegativity between carbon and oxygen, resulting in a net dipole moment.
Trigonal Pyramidal. It is not trigonal planar because there is one lone pair around the central atom, just like the shape of ammonia.