Respuesta :

Step-by-step explanation:

[tex] {14}^{2} = 2 {a}^{2} \\ 2 {a}^{2} = 196 \\ {a}^{2} = 98 \\ a = \sqrt{98 } = \sqrt{49 \times 2} \\ = 7 \sqrt{2} [/tex]