Understanding Circles and Circumference

What is the term for the distance from the center of a circle to any point on its edge?

• Perimeter

• Radius

• Circumference

• Diameter

Which formula represents the circumference of a circle using its diameter?

• C = d/π

• C = πd

• C = 2πr

• C = 2d

If the diameter of a circle is 12 inches, what is the approximate circumference using π as 3.14?

• 37.68 inches

• 36.68 inches

• 35.68 inches

• 38.68 inches

When rounding 37.68 to the nearest tenth, what is the result?

• 37.6

• 37.7

• 37.8

• 37.5

Which formula should be used to find the circumference when only the radius is given?

• C = r/π

• C = 2d

• C = 2πr

• C = πd

If the radius of a circle is 7.1 meters, what is the approximate circumference using π as 3.14?

• 44.6 meters

• 46.6 meters

• 45.6 meters

• 43.6 meters

What is the minimum diameter of a hole needed if the circumference of a tree's root bulb is 110 inches?

• 37 inches

• 34 inches

• 35 inches

• 36 inches

How do you solve for the diameter if the circumference is known?

• Divide circumference by π

• Subtract π from circumference

• Multiply circumference by π

• Add π to circumference

What is the value of π used in the examples?

• 3.13

• 3.15

• 3.16

• 3.14

In the real-world problem, what is the circumference of the tree's root bulb?

• 130 inches

• 110 inches

• 100 inches

• 120 inches