show/hide this revision's text 2 added an answer to the other question

For question 2, the best known is due to Ruth Kellerhals (the answer is here)

And for question 1, the latest (but, judging from the math review, not greatest) is Gehring/Martin.

show/hide this revision's text 1

For question 2, the best known is due to Ruth Kellerhals (the answer is here)