How does the norm of a cross product in 3-space give squared units?

Question

It has been given in my textbook that the area of a parallelogram whose distinct sides are formed by the vectors v and u is $\|v\times u\| $. But why would the norm of the cross product $(x,y,z)$ be a squared unit? I'm thinking that taking the norm maps a vector to a length, which is not a squared unit.