Area and Circumference of Circles

Front

What is the formula for 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

What is the distance around a circle called?

Back

Circumference.

Front

If a circle has a radius of 7 cm, what is its circumference?

Back

Circumference = 2 × π × 7 cm ≈ 43.96 cm.

Front

What is the formula for the area of a circle?

Back

Area = π × radius².

Front

If a circle has a radius of 5 cm, what is its area?

Back

Area = π × (5 cm)² ≈ 78.5 cm².

Front

What is the diameter of a circle?

Back

The diameter is twice the radius (Diameter = 2 × radius).

Front

If the diameter of a circle is 10 ft, what is the radius?

Back

Radius = Diameter / 2 = 10 ft / 2 = 5 ft.

Front

How do you convert diameter to radius?

Back

Divide the diameter by 2.

Front

What is the area of a circle with a diameter of 12 ft?

Back

Area = π × (6 ft)² ≈ 113.04 ft².