1.  The angle of elevation of a ladder leaning against a wall is 60º and the foot of the ladder is 4.6 m away from the wall. The length of the ladder is:
A. 2.3 m
B. 4.6 m
C. 7.8 m
D. 9.2 m

Answer: Option D

Explanation:

Let AB be the wall and BC be the ladder.

Then, ACB = 60º and AC = 4.6 m.

AC = cos 60º = 1
BC 2

BC = 2 x AC
= (2 x 4.6) m
= 9.2 m.