Hey

First draw the Lewis dot structure:
Electron geometry: tetrahedral. Hybridization: sp 3

Then draw the 3D molecular structure using VSEPR rules:

Decision:
The molecular geometry of SiH 4 is tetrahedral with symmetric charge distribution around the central atom.
Therefore this molecule is non- planer

The molecular geometry of PCl 5 is trigonal bipyramid with symmetric electron region distribution around the central atom.

I Hope It Helps

Good Luck