Here is a little brain teaser:
I needed to rake my mast
back to get a little more weather helm
(it helps me go to windward).
I lengthened the forestay by extending the turnbuckle, which let the top of the mast
I took in the slack in the backstay by the same method.
Now, say I let out 10" on the forestay, how far back did the top of the mast move?
I needed a quick and easy answer and I found one which took about 3 minutes.
What is it?
Clue: use trig and don't worry if the answer is imprecise.