## Rectangular Prism

Given the right rectangular prism shown, how many different planes can you find that contain point $B$ and also pass through another vertex of the prism?

Source: NCTM Mathematics Teacher 2008

SOLUTION
$3$ faces of the prism: $BADC,BAEF,BCGF$
$3$ diagonal planes: $BEHC,BFHD,BAHG$
$3$ 3-point planes: $BDE,BDG,BEG$

Answer: $9$