[SOLVED] Related Rates - Sort of confused 1. The problem statement, all variables and given/known data There are two buildings. One 20' high and other 40' high with a 60' distance between them. A person walking between them creates a theta with the buildings (see pic) PICTURE: http://allyoucanupload.webshots.com/v/2003959771064888674 Now i am asked to find maximum theta possible if the person is walking 4ft/s to the left. 2. Relevant equations ? 3. The attempt at a solution I am kind of lost in coming up with the relation between theta and the two buildings. I know once i get the relation in terms of theta, i can take the derivative and find when the derivative = 0 and see if thats a max. But any help with finding this equation would be greatly appreciated. Thanks!