Finding Circumference

Front

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

Back

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

Front

What is the value of π (pi) approximately?

Back

π is approximately 3.14.

Front

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

Back

Circumference = π × diameter = 3.14 × 10 = 31.4 inches.

Front

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

Back

Circumference = 2 × π × radius = 2 × 3.14 × 5 = 31.4 cm.

Front

How do you convert diameter to radius?

Back

Radius = diameter ÷ 2.

Front

What is the circumference of a circle with a diameter of 8 m?

Back

Circumference = π × diameter = 3.14 × 8 = 25.12 m.

Front

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

Back

Diameter = Circumference ÷ π = 62.8 ÷ 3.14 = 20 cm.

Front

What is the relationship between radius and diameter?

Back

The diameter is twice the length of the radius.

Front

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

Back

Circumference = 2 × π × radius = 2 × 3.14 × 3 = 18.84 inches.

Front

If a circle has a circumference of 31.4 inches, what is its radius?

Back

Radius = Circumference ÷ (2 × π) = 31.4 ÷ (2 × 3.14) = 5 inches.