Area and Circumference of the Circle

Front

What is the formula for finding the area of a circle?

Back

Area = πr², where r is the radius.

Front

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

Back

Circumference = 2πr, where r is the radius.

Front

What does π (Pi) equal?

Back

π is approximately 3.14.

Front

What is the radius of a circle?

Back

The radius is the distance from the center of the circle to any point on its circumference.

Front

What is the diameter of a circle?

Back

The diameter is twice the radius, or the distance across the circle through its center.

Front

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

Back

Area = π(5)² = 78.5 cm² (using π ≈ 3.14).

Front

If the radius of a circle is 7 inches, what is the circumference?

Back

Circumference = 2π(7) = 43.96 inches (using π ≈ 3.14).

Front

What is the relationship between diameter and radius?

Back

The diameter is equal to 2 times the radius (D = 2r).

Front

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

Back

Radius = Diameter / 2.

Front

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

Back

Area = π(3)² = 28.26 cm² (using π ≈ 3.14).