RotateShape

*To*: mathgroup at smc.vnet.net*Subject*: [mg29663] RotateShape*From*: Stephen Weil <stephenweil at yahoo.com>*Date*: Mon, 2 Jul 2001 02:20:24 -0400 (EDT)*Sender*: owner-wri-mathgroup at wolfram.com

Hi, I am trying to rotate a regular tetrahedron around an axis that goes through the center of the tetrahedron and one of its vertices. Rotating around the top vertex is simple it's just RotateShape[tet,0,0,Pi/2]. But I haven't been able to rotate about one of the three other axes. I tried: RotateShape[tet,0,Pi-2ArcSin[Cos[Pi/3]/Sin[Pi/3]],Pi/2] where the x-axis rotation angle is the angle between the line joining any one vertex to the center and any other vertex to the center, it's Pi minus the dihedral angle. The first z-axis rotation angle should be either -2Pi/3, 0 or 2Pi/3 depending on which vertex is being rotated. But all I get is a wobbly tetrahedron! Grateful if anyone could assist me. Regards, Stephen Weil __________________________________________________ Do You Yahoo!? Get personalized email addresses from Yahoo! Mail http://personal.mail.yahoo.com/