Choose the correct answer of the following question:
A ladder makes an angle of 60° with the ground when placed against a wall. If the foot of the ladder is 2 m away from the wall, then the length of the ladder is
(a) $\frac{4}{\sqrt{3}} \mathrm{~m}$
(b) $4 \sqrt{3} \mathrm{~m}$
(c) $2 \sqrt{2} \mathrm{~m}$
(d) $4 \mathrm{~m}$
Let AB be the wall and AC be the ladder.
We have,
$\mathrm{BC}=2 \mathrm{~m}$ and $\angle \mathrm{ACB}=60^{\circ}$
In $\Delta \mathrm{ABC}$,
$\cos 60^{\circ}=\frac{\mathrm{BC}}{\mathrm{AC}}$
$\Rightarrow \frac{1}{2}=\frac{2}{\mathrm{AC}}$
$\therefore \mathrm{AC}=4 \mathrm{~m}$
Hence, the correct answer is option (d).
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