Why Does a Telephoto Lens Have a Longer Focal Length Than a Single Convex Lens?

[copitlory8]

1. Why is a telephoto lens considered to have a longer focal length than that of a single convex lens?

A lens combination, such as a diverging and a convex lens, is referred to as a telephoto lens. Suggest why a telephoto lens is considered to have a longer focal length than that of a single convex lens.

 

[Delphi51]

If you just look at a camera with a telephoto lens, the distance from the front of the lens to the sensor inside the camera is very large.