Respuesta :

ivystorm
The diameter of the circular foundation would be 18.8 feet, and the circumference would be 59.1 feet.
dsaketh
The diameter in a circle is twice the radius which is 18.8 in this situation.

Circumference is 2 * π * r

just substitute the values                        In geometry they use 3.14 for pi                                                                       sometimes
so it would be 2 * 3.14* 9.4
= 59.03