You Rit. We also can use similar tringles and ...getting h(r-h)=

所有跟帖： 

• (R+r-h)^2=(R+r)^2-R^2-h^2,... -jinjing- ♀ (0 bytes) () 08/15/2011 postreply 17:31:02

• Sorry, It should be: (R+r-h)h=(R+r)^2-R^2-h^2,... -jinjing- ♀ (0 bytes) () 08/15/2011 postreply 17:33:49