A20 foot ladder rests against the top of a 15 foot building. how far does the ladder extend from the base of the wall and what angle does the ladder make with the ground?

Look at the picture.

Calculate x using the Pythagorean theorem:


Calculate α using sine:


The ladder extends approximately 13.23 feet (exactly: 5√7 feet) from the base of the wall and makes an approximately 49° angle with the ground.