Answer:
[tex] \frac{ \sqrt{3} }{2} x = 15 \\ x = \frac{30}{ \sqrt{3} } = 10 \sqrt{3} \\ \\ area = \frac{3 \sqrt{3} }{2} {x}^{2} = 15 \times 3 \times 10 \sqrt{3} = 450 \sqrt{3} [/tex]