Question: One of the contests at the school carnival is to throw a spear at an underwater target lying flat on the bottom of a pool. The water is 1.10m deep. You're standing on a small stool that places your eyes 2.90m above the bottom of the pool. As you look at the target, your gaze is 30 degree below horizontal.

Part A: At what angle below horizontal should you throw the spear in order to hit the target?

I want help to find at what angle below horizontal you should throw the spear in order to hit the target.