Using the information below, please find and explain how you found the height of the clocktower. (Note: It is possible that you won't need some of the information below to find the height of the clocktower)

Question

Bobby, who is 5’6” tall, took a square of paper, folded it in half and then taped a straw to the hypotenuse. Then holding the bottom of the paper level, he walked back from the clocktower until he could sight the top of the clocktower through the straw. At that point he was 42 feet from the clocktower. He also noted his shadow was 8 ft long. 2 hrs later, he came back and measured the clocktower’s shadow and it was 20 ft long.

Answer 1

I did this same question yesterday, but with jiskha's new format, which was
introduced last year, it is now impossible to find anything any more.
If you are patient enough you might be able to backtrack and find it