Pre-Honors Chemistry : Tip to Memorize Molecular Shapes:
There's not a whole lot online about memorizing molecular shapes so I thought I'd throw my method out there. There's really not a whole lot to it other than good ol' fashioned memorization but I personally found my way of memorizing it to be easiest.
1. For bent molecular geometry when the electron-pair geometry is trigonal planar the bond angle is slightly less than 120 degrees, around 118 degrees.
2. For trigonal pyramidal geometry the bond angle is slightly less than 109.5 degrees, around 107 degrees.
3. For bent molecular geometry when the electron-pair geometry is tetrahedral the bond angle is around 105 degrees.