Circumference and Area in terms of pi

Front

What is the formula for the area of a circle?

Back

Area = π × r², where r is the radius.

Front

What is the formula for the circumference of a circle?

Back

Circumference = 2 × π × r, where r is the radius.

Front

If the radius of a circle is 3 cm, what is the area?

Back

Area = π × (3 cm)² = 28.26 cm².

Front

If the diameter of a circle is 21 feet, what is the circumference?

Back

Circumference = π × 21 ft = 65.94 ft.

Front

What does 'circumference' mean?

Back

Circumference is the distance around a circle.

Front

If a cookie has a radius of 5 inches, what is its circumference?

Back

Circumference = 2 × π × 5 in = 31.4 in.

Front

What is the area of a circle with a radius of 13 cm?

Back

Area = π × (13 cm)² = 530.66 cm².

Front

What is the value of π (pi) approximately?

Back

π is approximately 3.14.

Front

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

Back

Radius = Circumference / (2 × π).

Front

What is the relationship between diameter and radius?

Back

Diameter = 2 × Radius.