Area and Circumference of a Circle

Front

What is the value of pi (π)?

Back

Approximately 3.14.

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 using the diameter?

Back

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

Front

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

Back

Diameter = 2 × radius = 20 ft.

Front

What is the area of a circle with a radius of 7.5 ft?

Back

Area = π × (7.5)² ≈ 176.63 ft².

Front

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

Back

Radius = Diameter ÷ 2.

Front

What is the relationship between diameter and circumference?

Back

Circumference = π × diameter.

Front

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

Back

Diameter = Circumference ÷ π ≈ 10 ft.

Front

What is the area of a circle with a diameter of 10 ft?

Back

Area = π × (5)² ≈ 78.54 ft².

Front

What is the formula for finding the circumference of a circle using the radius?

Back

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