**Skill 50 Calculate the Measures of a Circle, a Sphere, or a Cylinder**

On the ASVAB, often there are questions that ask you to find certain measures of a circle. You may even have to calculate the volume of a *sphere* (a round three-dimensional object) or a *cylinder* (a solid with circular surfaces on either end). The good news is that there are no sides to add up!

Let’s start by defining some terms.

• The **radius** of a circle is the distance from the center to any point on the edge.

• The **diameter** of a circle is a straight line from one side of a circle to the opposite side, passing through the center. The diameter is twice the length of the radius.

• The **circumference** of a circle is the distance around its outside edge. The circumference is the ...