minta bantuannya, nomer 22:)

luas = p × l
[tex]9 = \sqrt{7} - 2 \times l \\ l = \frac{9}{ \sqrt{7} - 2} = \frac{9}{ \sqrt{7 - 4} } = \frac{9}{ \sqrt{3} } = \frac{ \sqrt{81} }{ \sqrt{3} } = \sqrt{27} = \sqrt{9} . \sqrt{3} = 3 \sqrt{3} [/tex]