which is unnecessary to include when accurately drawing ray diagrams?\no focal point\no lens\no focal…

Brief Explanations:

In ray - diagrams for lenses, the focal point, the lens itself, and three standard rays (parallel to the axis, through the optical center, and through the focal point) are crucial. The focal length is a property related to the focal point and is used conceptually but not always explicitly drawn as a separate entity in the ray - diagram itself.

Answer:

focal length