But also for getting that exact same shape you show it may be easier to export it from your polygon program and bring the wireframe into MoI. You can do that by exporting from your polygon program in OBJ format, then run the OBJ to 3DM wireframe converter on it from here: http://moi3d.com/wiki/Resources#Obj23dmWireframe_converter that will then produce a 3DM file that has all the lines that you need - go in and select 3 lines at a time and run the Construct > Planar command, select another 3 lines and right-click to repeat until you have filled in all the planes and then use Edit > Join to glue them together.