Consider the following problem:

A ladder 10 feet long rests against a vertical wall. If the bottom of the ladder slides away from the wall at a rate of 4 feet per second, how fast is the top of the ladder sliding down the wall when the bottom of the ladder is 6 feet from the wall?

How many variables are present in this scenario? What is the “giveaway” that this is a related rate problem? What geometric objects would be relevant to describe the variables here pictorially and why?

Note: you DO NOT need to solve the problem to answer these questions.