Finding Circumference

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

Back

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

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

What does circumference measure?

Back

Circumference measures the distance around a circle.

Front

If the radius of a circle is doubled, how does the circumference change?

Back

The circumference also doubles.

Front

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

Back

Circumference = 2 × π × 3 = 18.84 m.

Front

What is the relationship between diameter and radius?

Back

Diameter = 2 × radius.

Front

If a circular track has a circumference of 400 m, what is its diameter?

Back

Diameter = Circumference / π = 400 / 3.14 ≈ 127.39 m.

Front

What is the circumference of a circle with a radius of 7 inches?

Back

Circumference = 2 × π × 7 = 43.96 inches.