Find the diameter and radius of a circle given the approximate circumference of 38 meters. (3.14 for pi)

Sorry for these questions but I just don't understand them; -;

Diameter = 12.1 radius = 6.05

Circumference = diameter x pi

38 = diameter x 3.14 (divide by pi on both sides of the equation to get diameter alone)

38/3.14 = diameter

12.1 = diameter

Radius = half of the diameter

Radius = 12.1/2 = 6.1

Diameter = 12.1meters, Radius = 6.1 meters