1."You see that section of pipe?" said Charlie, pointing towards his office building. "It's a true cylinder." Tom looked. "Yes, the one lying close up against the wall with a ladder set over it. What about it?" he replied. Charlie smiled. "The ground is level. The top of the ladder is 15 feet up the wall, its foot 8 feet from the wall, and the ladder just touches the pipe." What is the diameter?

Pipe diameter seven feet

Pipe diameter four feet

Pipe diameter six feet