What is the angle between (vec A+ vec B) and (vec A xx vec B) ?`

Explanation

` (vec A+ vec B) = vec C` (say ) . It lies in the plane of
` vec A and vec B`. (`vec A xx vec B`) = `vec D ` (say). It lies perpendicular to the plane of ` vec A and vec B`.
Therefore angle between ` vec Cand vec D` is 90^(@)`.