Vectors/planes and lines

[Ttwnycorporation]

Good morning/afternoon, I would like to request some help with question 8a).

How do I find the position vector of point S?

I only need this 1 point to start the question, but I can't seem to find it. Thank you and have a nice day.

 

[Dr.Peterson]

You might find vector B'S using the given angle [MATH]\theta = \angle C'B'S[/MATH]. S is directly above the midpoint of BC.