Circumference

Front

What is the formula for calculating 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

If the radius of a circle is 7 cm, what is the circumference?

Back

Circumference = 2 × π × 7 cm ≈ 43.96 cm.

Front

What is the relationship between diameter and radius?

Back

Diameter = 2 × radius.

Front

What is the diameter of a circle with a radius of 5 cm?

Back

Diameter = 2 × 5 cm = 10 cm.

Front

What is the radius of a circle with a circumference of 31.4 cm?

Back

Radius = Circumference / (2 × π) ≈ 5 cm.

Front

True or False: The diameter is the distance from the center to any point on a circle.

Back

False. The diameter is the distance across the circle through the center.

Front

What is the radius of a circle with a diameter of 20 cm?

Back

Radius = Diameter / 2 = 10 cm.

Front

If a circle has a circumference of 62.8 cm, what is its diameter?

Back

Diameter = Circumference / π ≈ 20 cm.

Front

What is the definition of a circle?

Back

A circle is a collection of points in a plane that are equidistant from a fixed point called the center.