Circumference Practice

Front

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

Back

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

Front

Find the circumference of a circle with a radius of 12.5 mm.

Back

78.5 mm.

Front

What is the diameter of a circle if the radius is 2.5 cm?

Back

Diameter = 2 × radius = 5 cm.

Front

What does 'circumference' mean?

Back

Distance around a circle.

Front

If the diameter of a circle is 14 cm, what is the circumference?

Back

43.96 cm.

Front

What is the radius of a circle with a diameter of 10 cm?

Back

Radius = Diameter / 2 = 5 cm.

Front

What is the relationship between diameter and radius?

Back

Diameter = 2 × radius.

Front

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

Back

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

Front

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

Back

Circumference = π × diameter ≈ 62.83 cm.

Front

What is the radius of a circle with a circumference of 62.83 cm?

Back

Radius = Circumference / (2 × π) ≈ 10 cm.