Exploring Circle Area and Circumference

Front

What is the formula for the circumference of a circle?

Back

The circumference (C) of a circle is given by the formula: C = 2πr, where r is the radius.

Front

What is the relationship between the diameter and radius of a circle?

Back

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

Front

How do you calculate the area of a circle?

Back

The area (A) of a circle is calculated using the formula: A = πr², where r is the radius.

Front

What is the value of π (pi)?

Back

π (pi) is approximately equal to 3.14, but it is an irrational number with an infinite number of decimal places.

Front

If a circle has a radius of 5 cm, what is its diameter?

Back

The diameter is 10 cm, since d = 2r = 2 * 5 cm.

Front

What is the circumference of a circle with a radius of 9 feet?

Back

The circumference is 18π feet, calculated as C = 2πr = 2π(9) = 18π.

Front

What is the diameter of a circle with a radius of 7 cm?

Back

The diameter is 14 cm, calculated as d = 2r = 2 * 7 cm.

Front

What is the circumference of a circle with a diameter of 15 meters?

Back

The circumference is 15π meters, calculated as C = πd = π(15) = 15π.

Front

If a circle has a diameter of 18 cm, what is its area?

Back

The area is 81π cm², calculated as A = πr² = π(9)² = 81π.

Front

What is the circumference of a circle with a diameter of 12 cm?

Back

The circumference is 12π cm, calculated as C = πd = π(12) = 12π.