The base of a ladder is 25 meters due west of a burning building. If the angle of elevation of the ladder is 51°, how long is the ladder (round to the nearest meter)? A)33 meters B) 34 meters C) 39 metersD) 40 meters

Distance from the building where the fireman is standing = 25 m due yo the west pointed  angle of elevation of the ladder = 51 degrees You then aquire the length of the ladder equals... 
x ThenCos 51 degree = 25/x0.6293
= 25/xx = 25/0.6293   = 39.72 meters≈40 meters from the above deduction, so the correct answer is D, because it is the closest, and that it is correct.