Circumference and Area

Front

What is π?

Back

The ratio of the circumference of any circle to its diameter.

Front

What is the formula for the area of a circle?

Back

Area = π × r², where r is the radius.

Front

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

Back

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

Front

What is the circumference of a circle?

Back

Circumference = π × d, where d is the diameter.

Front

How do you calculate the area of a circle with a radius of 4 cm?

Back

Area = π × (4 cm)² = 16π cm² or approximately 50.27 cm².

Front

What is the relationship between diameter and circumference?

Back

Circumference = π × diameter.

Front

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

Back

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

Front

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

Back

Area = π × (6 inches)² = 36π in² or approximately 113.10 in².

Front

How do you find the circumference of a circle with a radius of 3 m?

Back

Circumference = 2π × radius = 2π × 3 m = 6π m or approximately 18.85 m.

Front

What is the area of a circle with a radius of 5 cm?

Back

Area = π × (5 cm)² = 25π cm² or approximately 78.54 cm².