[Chimera-users] Help or feature request

It's a very common problem to calculate the twist angle between to beta-strands or two alpha-helix. So I am wondering if Chimera can fit a group of atoms into a straight line, and give the angle of two fitted line. If chimera does do this, hopefully somebody can tell me how to do this. If not, it would be worthwhile to add this function in. Thank you very much! Happy holiday! Mingfeng