Question

A ladder 15 m long just reaches the top of a vertical wall. If the ladder makes an angle of 60° with the wall, then the height of the wall is
A. 15√3m
B. 15√3/2m
C. 15/2m
D. 15 m

Answer 1

Answer:

Step-by-step explanation:

Answer 2

C. 15/2m

Step-by-step explanation:

In triangle ABC, we get angle A = 60, angle C = 90.

The ladder forms the hypotenuse AB, which is 15m long. AC is the wall. Distance between wall and ladder is BC, which is the opposite side. Let height of the wall (Adjacent side) be x.  

AC = x

AB = 15m

Cos 60 = adjacent / hypotenuse

 1/2 = x/15

 Therefore x = 15/2 = 7.5m

Option C is the answer.