In reply to Deadeye:
I just used the cosine rule:
a^2 = b^2 + c^2 -2bcCos(A)
Where a^2 is Length C to A, and angle A is angle CBA.
this gives: L^2 + R^2 = c^2 (pythagoras)
and c^2 = R^2 +T^2 -2RT*Cos(x), where x is angle CBA
and x = 90-y say, where y is required angle
simplifying gives:
L^2 =T^2 -2RT*Cos(y-90)
therefore y =arccos ((T^2-L^2 )/2RT)+90.
now to look through everyone elses solutions!
Edit: just seen you can tidy this up by transforming cos(y-90) to sin(y).
So I get: y =arcsin ((T^2-L^2 )/2RT)
Is everyone else getting this too? OP, what’s the correct solution? My solution seems slightly different to everyone elses.
Post edited at 12:00