Do you know what a cross product is?
You could use it to get a vector that is orthogonal to both u and w.
However in this case, itīs clear that both u and v are in the xy plane so to speak. So you will get a normal pointing "straight up" from the xy-plane.
You will need your normal to satisfy . So you get . Note here that the means dot-product.
So you have a plane parallell to the xy-plane, with perpendicular distance of 3 to the origin.