Help I am STRUGGLING

Diameter of a circle = circumfrence / pi 

d = 56.55 / 3.14

d = about 18.01

The diameter of the circle is about 18.01 meters long. 

so the circumference of the circle is 56.55

$Circumference=diameter \times \pi \\ d={c\over \pi} \\ d={56.55\over\pi}=18(aprox.)$