Area and Circumference of Circles

Front

What is the distance halfway across the circle called?

Back

Radius

Front

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

Back

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

Front

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

Back

5 cm

Front

What is the area of a circle with a radius of 3 cm?

Back

Area = π × (3 cm)² = 28.27 cm² (approximately)

Front

What is the relationship between diameter and radius?

Back

Diameter = 2 × radius

Front

If the circumference of a circle is 31.4 cm, what is the diameter?

Back

Diameter = 10 cm (using the formula Circumference = π × diameter)

Front

What is the circumference of a circle with a radius of 4 cm?

Back

Circumference = 2 × π × 4 cm = 25.13 cm (approximately)

Front

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

Back

Area = π × (7 cm)² = 153.94 cm² (approximately)

Front

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

Back

Diameter = 20 cm (using the formula Circumference = π × diameter)

Front

Is the line segment connecting the center of the circle to any point on the circle a radius or diameter?

Back

Radius