b) 4.6 m
c) 7.8 m
d) 9.2 m
Answer: d
Explanation: Let AB be the wall and BC be the ladder.
Then, ∠ACB = 60° = AC = 4.6m
$$\frac{{AC}}{{BC}} = \cos {60^ \circ } = \frac{1}{2}$$
⇒ BC = 2 × AC = 2 × 4.6 = 9.2m
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: d
Explanation: Let AB be the wall and BC be the ladder.
Then, ∠ACB = 60° = AC = 4.6m
$$\frac{{AC}}{{BC}} = \cos {60^ \circ } = \frac{1}{2}$$
⇒ BC = 2 × AC = 2 × 4.6 = 9.2m
b) 4.6 m
c) 7.8 m
d) 9.2 m
Answer: d
Explanation: Let AB be the wall and BC be the ladder.
Then, ∠ACB = 60° = AC = 4.6m
$$\frac{{AC}}{{BC}} = \cos {60^ \circ } = \frac{1}{2}$$
⇒ BC = 2 × AC = 2 × 4.6 = 9.2m
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