Answer:
Diameter is the width = Â 7.64 ft
Step-by-step explanation:
Perimeter would need to be the arc of a semi circle measuring less than or equal to 12  Where perimeter therefore = 12* 2 = 24  24 / 3.14 = 7.64331210191  where 3.14 the value for pi  and formula of a semi circle we use radius  =  1/2 pi * 3.82 ^2 =  D * pi = 7.65  and radius =7.64 / 2 = 3.82 so answer is the diameter =   7.64 ft