help me? ocr mei a level vectors

You have to take the normal vector of both and find the angle between them. (0,0,1) is the normal vector of the horizontal plane (z=0)

where does the 0 0 1 come from though i dont really get it

The ground level is represented here as the plane 0x+0y+z=0 (same as z=0). To find the normal vector you always take the coefficients of the x,y and z. The coefficient of x is 0, y is 0 and z is 1 so we get the normal vector to this horizontal plane as (0,0,1)

why is z the horizontal plane wouldnt that be x?

It lies on the x axis but that doesn't make x the horizontal plane. If you think about all the points on the plane, x and y are always changing as you move around the plane but z is always 0 at all points on that plane so the plane has to be z=0.

ahh okay sorry im being useless here, how do you actually get 0 0 1 then i know you said coefficients but surely the ground level is just zero for all

Yes the ground level is 0 for z but the normal vector has to be 0,0,1 as it is normal to the plane