ABCD is the base of a square pyramid of side 2 units, and V is the vertex. The pyramid is symmetrical, and of height 4 units. Calculate the acute angle between AV and BC, giving your answer in degrees correct to 1decimal place.

I do not necessarily need the full solution. I just need to change it into position vectors so that I can solve it using dot product (scalar product).

I was able to do it for some other shapes but I just can't think how to apply it on a pyramid.