I'm just pleased that I finally found a math puzzle on HN that I was able to solve without looking ahead! (Although I called the radius of the cylinder r/a, wh

I'm just pleased that I finally found a math puzzle on HN that I was able to solve without looking ahead! (Although I called the radius of the cylinder r/a, where r is the radius of the sphere, which ended up making my math a bit messy...) Regardless, deserves an upvote just for the cheat answer at the end. I like that kind of reasoning!