Solution
= Solution
The direction <vectors> are $\mathbf u=(1,-2,1)$ and $\mathbf v=(0,-2,1)$. Their <cross product> is $(0,-1,-2)$, with <norm> $\sqrt5$. A <unit normal> to the plane is therefore
$$
\boxed{\mathbf n=\frac{(0,1,2)}{\sqrt5},\quad\text{or its negative}.}
$$
The two intersecting directions span the plane, so a <vector> <orthogonal> to both is a <normal vector> to that plane.