Răspuns:
[tex]A . \ 27\sqrt{3} \ cm^{2}[/tex]
Explicație pas cu pas:
[tex]h = \frac{l \sqrt{3} }{2} = 9 \\ [/tex]
[tex]l = \ \frac{ \sqrt{3} }{2} : 9 = \frac{ 2}{ \sqrt{3} } \cdot9 = \frac{ {}^{ \sqrt{3} )} 18}{\sqrt{3} } = \frac{ \not18 \sqrt{3} }{ \not3} = 6 \sqrt{3} \: cm \\ [/tex]
[tex]A = \frac{ {l}^{2} \sqrt{3} }{4} = \frac{(6 \sqrt{3} ) {}^{2} \cdot \sqrt{3} }{4} = \frac{108 \sqrt{3} }{4} =\boxed{ 27 \sqrt{3} \: cm {}^{2}} \\ [/tex]
