If I know what you're asking, the answer is theoretical probability.
Check the picture below.
notice AB ⟂ BC , whilst ∡B = 30°.
now, if we run a perpendicular line from C to AB, it'll be a 90° angle at M, however ∡AMC has to be 105°, so it has to be slanted more towards A, like in the picture, and surely you already know which one is the shortest.
No, because if y is in fact 9 then the expression
evaluates to
which is a false hence y cannot be 9 but rather
.
Hope this helps.