If a cylinder meets a plane, as in the attached image, what is the name for the line (red) along which they touch? Is it "tangent line" or something to this effect? For clarity, the normal vector of the plane in question is orthogonal to the long axis of the cylinder in question, and the plane is not intersecting the cylinder--it is resting on top of the cylinder along some line.
Thank you.
Moving triad vectors $T,N,B$ are pair-wise made by cutting between tangent, osculating and normal planes for a doubly curved surface. Here it is a singly curved cylindrical surface. Even if there is no tangent plane and the reference point moves along the shown cylinder generator line, it is envelope of tangent lines is the curve referred to in differential geometry.
If the additionally contact plane is included in the scene we could call it a line of tangential contact.
