A20-foot later leaning against the side of a house makes an 45° angle with the ground. how far up the side of the house does the ladder reach?

If you visualize the problem, you're looking at a right triangle with a hypotenuse of 20 and an acute angle with the ground of 45 degrees.

Use sin(45)*20 and you come up with 14.1421 as the height of the ladder

The answer to your question is i think 7

1.3 and 1 1/3 are both closest to 1. hope this ; )