Front

What is the formula for the circumference of a circle?

Back

C = 2πr or C = πd, where C is circumference, r is radius, and d is diameter.

Front

If the radius of a circle is 6 cm, what is the diameter?

Back

12 cm

Front

What is the relationship between diameter and radius?

Back

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

Front

If the diameter of a circle is 32 inches, what is the radius?

Back

16 inches

Front

What is the circumference of a circle with a radius of 5 inches?

Back

31.4 inches.

Front

How do you calculate the radius from the circumference?

Back

r = C / (2π).

Front

What is the circumference of a circle with a diameter of 21 feet?

Back

65.94 feet.

Front

If the diameter is 19 inches, what is the radius?

Back

9.5 inches.

Front

What does π (pi) represent in circle calculations?

Back

π is a constant approximately equal to 3.14, representing the ratio of the circumference to the diameter of a circle.

Front

How can you find the circumference if you only know the radius?

Back

Use the formula C = 2πr.