Your problem is really quite simple. First you need to find they diameter of the tenon (we'll call this X), then divide that by pi. Once you have that take the radius of the chuck and multiply by Y and take the cosine of your answer and find the square root. Once you have the square root, solve the problem- a passenger train leaves the train depot 2 hours after a freight train left the same depot. The freight train is traveling 20 mph slower than the passenger train. Find the rate of each train, if the passenger train overtakes the freight train in three hours. (don't forget to show your work)
In all seriousness, I have no idea how to help you with your problem but welcome to the forum. These guys are great and very helpful to newbies.