Respuesta :

A/B : 4/9 = 12/B
         cross multiply
         (4)(B) = (9)(12)
         4B = 108
         B = 108/4
         B = 27

P = 4a...where a is the length of one side
P = 4(27)
P = 108 yds <=== perimeter of square B
         
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