Area and Circumference of Circles

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 circumference of a circle?

Back

The circumference is the distance around a circle.

Front

If the radius is 6 cm, what is the circumference?

Back

The circumference is 37.68 cm (C = 2πr, where r = 6 cm).

Front

What is the diameter of a circle?

Back

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

Front

If the diameter is 10 in, what is the radius?

Back

The radius is 5 in (r = d/2, where d = 10 in).

Front

What is the formula for the circumference of a circle?

Back

C = 2πr or C = πd.

Front

What is π (pi)?

Back

π (pi) is a mathematical constant approximately equal to 3.14, representing the ratio of the circumference of a circle to its diameter.

Front

If the radius is 8 inches, what is the circumference?

Back

The circumference is 50.24 inches (C = 2πr, where r = 8 inches).

Front

What is the relationship between radius and diameter?

Back

The diameter is twice the radius (d = 2r).

Front

What is the area of a circle?

Back

The area is the space inside the circle, calculated as A = πr².