Respuesta :

Gotenks99

15.7

Step-by-step explanation:

rate as BRAINLIEST

[tex]a {}^{2} + {b}^{2} = {c}^{2} [/tex]

[tex] {a }^{2} + {(14)}^{2} = {(21)}^{2} [/tex]

[tex] {a}^{2} + 196 = 441 \\ {a}^{2} = 245 \\ \\ a = 15.65[/tex]