Răspuns:
[tex] \sqrt{52} = \sqrt{ {2}^{2} \times 13} = 2 \sqrt{13} [/tex]
[tex] \sqrt{208} = \sqrt{ {2}^{4} \times 13} = 4 \sqrt{13} [/tex]
[tex]a = 6 \sqrt{13} [/tex]
rad13 = aprox. 3,6
6 × 3,6 = 21,63
a > 19
