Answer: Choice D) 13 inches
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Work Shown:
C = circumference = 40 inches
d = diameter
[tex]C = \pi*d\\\\C \approx 3.14*d\\\\40 \approx 3.14*d\\\\\frac{40}{3.14} \approx d\\\\d \approx \frac{40}{3.14}\\\\d \approx 12.73885\\\\d \approx 13\\\\[/tex]
Be careful. Technically 12 inches is the largest diameter Tanya can use since 3.14*12 = 37.68 is under 40; while 3.14*13 = 40.82 is slightly over 40
So if I was the teacher, I would have said "round down to the nearest inch".
