Question

Find the distance from Q=(3,6,4) to the plane n ⋅⟨x,y,z⟩=2 where n=⟨3/5,4/5,0⟩.

L=?

Answer 1

this will probably help. It discusses how your question is just an extension of the distance from a point to a line.

mathinsight.org/distance_point_plane