Circumference of a Circle

Front

What is the formula for the circumference of a circle?

Back

Circumference = π × diameter (C = πd)

Front

What is the value of π (pi) approximately?

Back

π (pi) is approximately 3.14.

Front

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

Back

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

Front

What is the relationship between radius and diameter?

Back

Diameter = 2 × radius.

Front

If the radius of a circle is 5 cm, what is the diameter?

Back

Diameter = 2 × radius = 2 × 5 = 10 cm.

Front

What is the circumference of a circle with a diameter of 4 m?

Back

Circumference = π × diameter = 3.14 × 4 = 12.56 m.

Front

How do you find the circumference if you only know the radius?

Back

Circumference = 2 × π × radius.

Front

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

Back

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

Front

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

Back

Diameter = Circumference / π = 31.4 / 3.14 = 10 cm.

Front

If a circle has a circumference of 18.84 cm, what is its diameter?

Back

Diameter = Circumference / π = 18.84 / 3.14 = 6 cm.