Circumference of Circles

Front

What is the formula for the circumference of a circle?

Back

The circumference (C) of a circle is calculated using the formula C = 2πr, where r is the radius.

Front

How is the diameter of a circle related to the radius?

Back

The diameter (d) of a circle is twice the radius (r), so d = 2r.

Front

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

Back

The circumference is C = 2π(5) = 10π or approximately 31.42 inches.

Front

What is the circumference of a circle with a diameter of 10 feet?

Back

The circumference is C = πd = π(10) = 10π or approximately 31.42 feet.

Front

What is the value of π (pi) approximately?

Back

π (pi) is approximately 3.14.

Front

How do you convert the circumference from terms of π to a decimal?

Back

To convert the circumference from terms of π to a decimal, multiply the coefficient of π by the approximate value of π (3.14).

Front

What is the circumference of a circle with a radius of 6 inches?

Back

The circumference is C = 2π(6) = 12π or approximately 37.68 inches.

Front

If a circular window has a diameter of 24 inches, what is the circumference?

Back

The circumference is C = π(24) = 24π or approximately 75.36 inches.

Front

What is the relationship between circumference and area in circles?

Back

Circumference measures the distance around the circle, while area measures the space inside the circle. They are related through the radius: Area = πr².

Front

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

Back

To find the diameter from the circumference, use the formula d = C/π.