question_answer

In a rectangle \[ABCD\], \[AB=15\,\,cm\], \[\angle BAC={{60}^{o}}\]¸then the length of side \[BC\]is

A) \[15\sqrt{2}\,\,cm\]                    

B) \[15\,\,cm\]

C) \[15\sqrt{5}\,\,cm\]        

D)        \[15\sqrt{3}\,\,cm\]  

Correct Answer: D

Solution :

\[\angle BAC={{60}^{o}}\] \[\therefore \]      \[\tan {{60}^{o}}=\frac{BC}{AB}\] \[\Rightarrow \]   \[\sqrt{3}=\frac{BC}{15}\] \[\Rightarrow \]   \[BC=15\sqrt{3}cm\]