[tex]36 =3{a}^{2} \frac{ \sqrt{2} }{2} \\ = > 3{a}^{2} = \frac{36}{1} \div \frac{ \sqrt{2} }{2} = \frac{36}{1} \times \frac{2}{ \sqrt{2} } = \frac{72}{ \sqrt{2} } - rationalizam \\ = > 3 {a}^{2} = \frac{72 \sqrt{2} }{2} = 36 \sqrt{2} \\ = > {a}^{2} = 12 \sqrt{2} \\ = > a = 2 \: \: \: {}^{4} \sqrt{18} [/tex]