Dimension from the function field
= Dimension from the function field
For an irreducible variety $X$ over a field $k$,
$$
\dim X=\operatorname{trdeg}_k k(X).
$$
Consequently birational irreducible varieties have the same dimension.
= Dimension from the function field
For an irreducible variety $X$ over a field $k$,
$$
\dim X=\operatorname{trdeg}_k k(X).
$$
Consequently birational irreducible varieties have the same dimension.