[tex] \sqrt{ {5}^{2} + \frac{ {5}^{2} \times {3}^{2} }{ {4}^{2} } } = \\ = \sqrt{25 + \frac{ {(5 \times 3)}^{2} }{16} } \\ = \sqrt{25 + \frac{ {15}^{2} }{16} } \\ = \sqrt{25 + \frac{225}{16} } \\ = \sqrt{ \frac{625}{16} } \\ = \frac{ \sqrt{625} }{ \sqrt{16} } \\ = \frac{25}{4} \\ = 6\frac{1}{4} \\ = 6.25[/tex]
