Me with problem 4 of a math problem

15 point ! ~ see if you know the answer to both you!

If your teacher tells you to do questions 6 through 19 in your math book for homework, how many questions is that

Aladder that is 20ft long is leaning against the side of a building. if the angle formed between the ladder and the ground is 75 degrees how far is the bottom of the from the base of the building?