Circumference of a Circle

Front

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

Back

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

Front

If a circle has a diameter of 10 inches, what is its radius?

Back

Radius = diameter / 2 = 10 inches / 2 = 5 inches.

Front

What is the value of π (pi) approximately?

Back

π (pi) is approximately 3.14.

Front

A circle has a radius of 7 inches. What is its circumference?

Back

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

Front

What is the relationship between diameter and radius?

Back

The diameter is twice the length of the radius.

Front

If the circumference of a circle is 31.40 inches, what is its diameter?

Back

Diameter = Circumference / π ≈ 31.40 inches / 3.14 ≈ 10 inches.

Front

What is the circumference of a circle with a radius of 3 inches?

Back

Circumference = 2 × π × 3 inches ≈ 18.84 inches.

Front

How do you convert diameter to radius?

Back

Divide the diameter by 2.

Front

What is the circumference of a pizza with a 12-inch diameter?

Back

Circumference = π × 12 inches ≈ 37.68 inches.

Front

If a circle has a circumference of 18.84 inches, what is its radius?

Back

Radius = Circumference / (2 × π) ≈ 18.84 inches / 6.28 ≈ 3 inches.