Given.

Let the angle between vectors and be θ.

We know the cross product of two vectors and forming an angle θ is

where is a unit vector perpendicular to and

is a unit vector

We also have the dot product of two vectors and forming an angle θ is

But, it is given that

⇒ sin θ = cos θ

⇒ tan θ = 1

Thus, the angle between two vectors is.