Respuesta :

Answer:

3 root 7

Step-by-step explanation:

h^2 = b^2 + a^2

12 square = b square + 9 square

144 = b^2 + 81

144-81 = b^2

63 = b^2

b = root of 63

b = root 7 x root 9                         ................( since 7x9=63)

b = 3 root 7                                 ..............( since root of 9 is 3)

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