Circumference of Circles

Front

What is the formula to calculate the circumference of a circle?

Back

Circumference = 2 × π × radius or Circumference = π × diameter.

Front

What is the value of π (pi) approximately?

Back

π is approximately 3.14.

Front

What is the relationship between diameter and radius?

Back

Diameter is twice the radius (Diameter = 2 × radius).

Front

If the radius of a circle is 5 cm, what is the circumference?

Back

Circumference = 2 × π × 5 cm ≈ 31.4 cm.

Front

What is the definition of circumference?

Back

Circumference is the distance around the circle.

Front

If the circumference of a circle is 31.4 cm, what is the diameter?

Back

Diameter = Circumference / π ≈ 10 cm.

Front

What is the definition of radius?

Back

Radius is the distance from the center of the circle to any point on the circle.

Front

If the diameter of a circle is 12 cm, what is the radius?

Back

Radius = Diameter / 2 = 6 cm.

Front

What is the definition of a circle?

Back

A circle is a set of all points in a plane that are the same distance from a point called the center.

Front

How do you find the radius if you know the circumference?

Back

Radius = Circumference / (2 × π).