Answer:
Electron pair geometry - tetrahedral
molecular geometry- trigonal pyramidal
Step-by-step explanation:
According to Valence Shell Electron Pair Repulsion Theory, the shape of a molecule is determined by the number of electron pairs around the central atom in the molecule. Lone pairs distort a molecule away from its expected geometry based on VSEPR. This is why the electron pair geometry differs from the actual molecular geometry.
PCl3 has four regions of electron density, three substituents and one lone pair hence its electron pair geometry is tetrahedral. However, the three substituents are arranged in a trigonal pyramidal geometry(its molecular geometry).