A) \[\frac{7\sqrt{3}}{2}\left( \sqrt{3}-1 \right)m\]
B) \[\frac{7\sqrt{3}}{2}\frac{1}{\sqrt{3}+1}m\]
C) \[\frac{7\sqrt{3}}{2}\frac{1}{\sqrt{3}-1}m\]
D) \[\frac{7\sqrt{3}}{2}\left( \sqrt{3}+1 \right)m\]
Correct Answer: D
Solution :
\[\tan {{60}^{o}}=\frac{h}{BC}\] ?. (i) and \[\tan {{45}^{o}}=\frac{h}{7+BC}\] ?. (ii) tan 45 ?(ii) \[\Rightarrow 7+BC=h\Rightarrow BC=h-7\] From(i)\[\sqrt{3}=\frac{h}{h-7}\Rightarrow \sqrt{3}h-7\sqrt{3}=h\Rightarrow \sqrt{3}h-h=7\sqrt{3}\] \[h=\frac{7\sqrt{3}}{\sqrt{3}-1}\Rightarrow \frac{7\sqrt{3}\left( \sqrt{3}+1 \right)}{2}m\]You need to login to perform this action.
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