Circumference Practice

Front

What is the formula to find 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 (Pi) is approximately 3.14.

Front

If the radius of a circle is 10 cm, what is the circumference?

Back

Circumference = 2 × π × 10 cm = 62.8 cm.

Front

What is the relationship between diameter and radius?

Back

Diameter = 2 × radius.

Front

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

Back

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

Front

What does the term 'circumference' refer to?

Back

Circumference is the distance around the outside of a circle.

Front

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

Back

Diameter = Circumference ÷ π.

Front

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

Back

Diameter = 31.4 cm ÷ π ≈ 10 cm.

Front

What is the radius of a circle with a circumference of 62.8 cm?

Back

Radius = Circumference ÷ (2 × π) = 62.8 cm ÷ (2 × 3.14) = 10 cm.

Front

If a semicircle has a radius of 7 m, what is its circumference?

Back

Circumference of semicircle = π × radius + diameter = 3.14 × 7 m + 14 m = 21.98 m.