your method only in special case can be OK.

來源: 於 2012-01-01 17:39:52 [舊帖] [給我悄悄話] 本文已被閱讀：次

The case is    alfa+(2m-1)beta=90 degree,m should be whole number. This Q is not ...

If I were boss, let beta=1d,alfa=11d,...I'm a little bit like a drunk now,...