The angle of elevation of a ladder leaning against a wall is 60° and the foot of the ladder is 4.6 m away from the wall. The length of the ladder is  Choose the correct option:
A) 2.3 m
B) 4.6 m
C) 7.8 m
D) 9.2 m
E) None
Solution   Let AB be the wall and BC be the ladder.   Then, &lt; ABC	= 60°   AC	= 4.6 m.;   AC/BC	= cos 60°   = 1 /2   ‹=›BC=2×AC   =(2× 4.6) m   = 9.2 m   Answer 9.2 m
<result>D</result>
The angle of elevation of a ladder leaning against a wall is 60° and the foot of the ladder is 4.6 m away from the wall. The length of the ladder is