By matrix-defined, I mean
x = | i j k | det(| a b c |) | d e f | $$\left<a,b,c\right>\times\left<d,e,f\right> = \left|
(\begin{array}{ccc} i & j & k\\ a & b & c\\ d & e & f \end{array}
\right|$$
...instead of the definition of the product of the magnitudes multiplied by the sign of their angle, in the direction orthogonal)
If I try cross producting two vectors with no k$k$ component, I get one with only k$k$, which is expected. ButBut why?
As has been pointed out, I am asking why the algebraic definition lines up with the geometric definition.