Compute the radius of the circle with a circumference of
109.9 millimeters.

The radius of the circle is 17.5 millimeters

Step-by-step explanation:

* Lets explain how to compute the radius of a circle from its

 circumference

- Circle is the locus of all points equidistant from a given point,

 this point is called the center of the circle.

- The distance from the center of the circle to a point on the circle is

 called the radius of the circle

- The circumference of a circle is the length of the closed cure

- The relation between the radius of a circle and its circumference is

 C = 2πr, where C is the circumference and r is the radius

* Lets solve the problem

- The circumference of a circle is 109.9 millimeters

- We need to find the radius of the circle

∵ The circumference of the circle = 109.9 millimeters

∵ The circumference of a circle = 2πr

- Substitute the value of the circumference in the equation above

∴ 109.9 = 2πr

- Divide both sides by 2

∴ 54.95 = πr

- Divide both sides by π (π ≅ 3.14)

∴ r = 17.49 ≅ 17.5

∴ The radius of the circle is 17.5 millimeters