Circumference and Area

Front

What is the value of π (pi)?

Back

3.14

Front

What is the formula for the circumference of a circle?

Back

Circumference = 2πr, where r is the radius.

Front

What is the formula for the area of a circle?

Back

Area = πr², where r is the radius.

Front

What is the relationship between diameter and radius?

Back

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

Front

If the radius of a circle is 9 cm, what is the area?

Back

Area = π(9)² = 254.34 cm².

Front

If the radius of a circle is 9 cm, what is the circumference?

Back

Circumference = 2π(9) = 56.52 cm.

Front

What is the diameter of a circle with a radius of 9 cm?

Back

Diameter = 2 * 9 = 18 cm.

Front

How do you convert from diameter to radius?

Back

Divide the diameter by 2.

Front

What is the approximate value of π to two decimal places?

Back

3.14

Front

What is the area of a circle with a diameter of 10 cm?

Back

Area = π(5)² = 78.54 cm².