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:
2.3 m
4.6 m
7.8 m
9.2 m
Explanation:
Let AB be the wall and BC be the ladder.
Then, $\angle$ACB = 60º and AC = 4.6 m.
$\dfrac{AB}{BC}$=cos 60°=1/2
$\Rightarrow$ BC = 2 x AC
= (2 x 4.6) m
= 9.2 m.
Let AB be the wall and BC be the ladder.
Then, $\angle$ACB = 60º and AC = 4.6 m.
$\dfrac{AB}{BC}$=cos 60°=1/2
$\Rightarrow$ BC = 2 x AC
= (2 x 4.6) m
= 9.2 m.