If `hat(a), hat(b), hat(c)` are unit vectors and `hat(a) xx (hat(b) xx hat(c)) = (1)/(2)hat(b)`, then find the angles that `hat(a)` makes with `hat(b)` and `hat(c)` where `hat(b), hat(c)` are not parallel.

Answer

`hat(a)` makes angle `90^(@)` with `hat(b)` and `60^(@)` with `hat(c )`