DL-1 throw distance

First off a small apology: I guess I should be able to figure the following stuff out for myself, but I thought I´d ask just to be sure:
If a DL-1 sits 4,6 meters (15,1´) from a wall, what size will the max image on that wall be?
And is it at all possible to change lens/optics to extreme wide angle if wanted?
I have a difficult customer