In the figure above, \(\frac{x}{\sin 60^o} = \frac{10}{\sin 30^o}\) (Sine rule) x = \(\frac{10 \sin 60^o}{\sin 30^o}\) = 10 x \(\frac{\sqrt{3}}{2} \times \frac{1}{2}\) = 10 x \(\frac{\sqrt{3}}{2} \times \frac{2}{1}\) = 10\(\sqrt{3}\)cm