Circumference of a Circle

Front

What is the formula to calculate the circumference of a circle?

Back

Circumference = 2 × π × radius or Circumference = π × diameter.

Front

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

Back

Diameter = 2 × radius = 10 cm.

Front

What is the value of π (pi) approximately?

Back

π (pi) is approximately 3.14.

Front

How do you find the circumference of a circle with a known diameter?

Back

Circumference = π × diameter.

Front

What is the circumference of a circle with a radius of 12.5 mm?

Back

78.5 mm.

Front

If a circle has a diameter of 20 ft, what is its radius?

Back

Radius = diameter ÷ 2 = 10 ft.

Front

What is the circumference of a pizza with a 10-inch diameter?

Back

31.40 inches.

Front

What is the relationship between radius and diameter?

Back

The diameter is twice the length of the radius.

Front

If Mia's bike wheels have a diameter of 14 inches, what is the circumference?

Back

43.96 inches.

Front

Is the red line in a circle a radius or diameter if it passes through the center and touches two points on the circle?

Back

Diameter.