The bottom of the ladder on a horizontal flat surface rests against a wall. It makes an angle of elevation of 35°. The bottom of the ladder is 42 ft from the base of the wall. How long is the ladder? Round your answer to the nearest whole number.



Answer :

You can use the cos Ф = base / hypotenuse.
 In this case, you have h = 42/cos 35 (approx. 0.819)
h = 42/0.819 = 51.3

To the nearest whole number, the length of the ladder is 51 feet.