Area and Circumference

Front

What is the definition of a radius in a circle?

Back

The radius is the distance from the center of the circle to any point on its circumference.

Front

What is the definition of a diameter in a circle?

Back

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

Front

How do you calculate the circumference of a circle?

Back

Circumference can be calculated using the formula C = πd, where d is the diameter, or C = 2πr, where r is the radius.

Front

What is the relationship between radius and diameter?

Back

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

Front

If the diameter of a circle is 16, what is the radius?

Back

The radius is 8 (since radius = diameter / 2).

Front

What is the formula for finding the area of a circle?

Back

The area A of a circle can be calculated using the formula A = πr², where r is the radius.

Front

If a circle has a radius of 2 ft, what is its diameter?

Back

The diameter is 4 ft (since diameter = 2 * radius).

Front

What is the circumference of a circle with a radius of 10 inches?

Back

The circumference is 62.8 inches (C = 2πr = 2 * π * 10).

Front

How do you find the radius if you know the circumference?

Back

You can find the radius by rearranging the circumference formula: r = C / (2π).

Front

What is the circumference of a circle with a diameter of 3 cm?

Back

The circumference is approximately 9.42 cm (C = πd = π * 3).