An I beam is positioned from points A to B. Because its strength and deformation properties for bending about an axis through the web of the cross section are different than those for bending about an axis parallel to the flanges, it is necessary to also characterize these directions. This can be accomplished by specifying just one of the direction angles for the direction of the web from A to C, which is perpendicular to line AB, plus the octant of the coordinate system in which line AC lies
(a) If direction angle θz = 30° for line AC, determine the remaining direction angles for this line.
(b) Determine the unit vector in the direction perpendicular to the web of the beam (i.e., perpendicular to lines AB and AC).
