Can someone help me with this? Please and thank you!

A20? -foot ladder is placed against a vertical wall of a? building, with the bottom of the ladder standing on level ground 19 feet from the base of the building. how high up the wall does the ladder? reach?

The depth of a lake at a certain point, wich is a function of the distance of that point from shore, is 30 feet.

This summer the number of tourists in salem increased 4.5% from last years total of 426000. how many more tourists came to salem this summer