Answer:
Step-by-step explanation:
If we think about a right triangle, we get that the hypotenuse is 24ft or the length of the ladder. The base of the ladder is 15ft away from the building which is the leg of the right triangle. The screenshot is the diagram (my drawing isn't that good lol:))
Thus we can use cosine function with the angle between the ladder and the ground since we need to find the angle and we get

and 
The angle is 51.3 degrees hope that helps!
It equals 45 degrees because if you have a ~ line it means you have 45 degrees and don't forget to thank me
4% is not equivalent to 40%
0.4 is equivalent to 40%. Just move the decimal two places to the right.
2/5 is equivalent to 0.4, which in turn is equivalent to 40%. 2 divided by 5=0.4
The answers are all but 4%