Finding Circumference

Front

What is the formula for calculating the circumference of a circle?

Back

The circumference (C) of a circle can be calculated using the formula C = 2πr, where r is the radius of the circle.

Front

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

Back

Using the formula C = 2πr, the circumference is C = 2π(5) = 31.42 cm.

Front

What is the value of π (pi) approximately?

Back

π (pi) is approximately 3.14.

Front

How does the circumference change if the radius of a circle is doubled?

Back

If the radius is doubled, the circumference also doubles, since C = 2πr.

Front

What is the circumference of a circle with a diameter of 10 m?

Back

Using the formula C = πd, where d is the diameter, the circumference is C = π(10) ≈ 31.42 m.

Front

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

Back

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

Front

If the circumference of a circle is 62.83 m, what is its radius?

Back

Using the formula C = 2πr, the radius can be found as r = C/(2π) = 62.83/(2π) ≈ 10 m.

Front

What units are used to measure circumference?

Back

Circumference is measured in linear units, such as meters (m), centimeters (cm), inches (in), or yards (yd).

Front

How do you convert the circumference from meters to centimeters?

Back

To convert from meters to centimeters, multiply the circumference in meters by 100 (1 m = 100 cm).

Front

What is the circumference of a circle with a radius of 3.5 ft?

Back

Using the formula C = 2πr, the circumference is C = 2π(3.5) ≈ 21.99 ft.