Radius, Diameter, Circumference Review

Front

What is the definition of the radius of a circle?

Back

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

Front

What is the definition of the diameter of a circle?

Back

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

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 = πd, where d is the diameter.

Front

If the radius of a circle is 7 cm, what is the diameter?

Back

The diameter is 14 cm (diameter = 2 x radius).

Front

If the diameter of a circle is 20 cm, what is the radius?

Back

The radius is 10 cm (radius = diameter / 2).

Front

What is the relationship between radius and diameter?

Back

The diameter is always twice the length of the radius.

Front

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

Back

Use the formula C = 2πr, where r is the radius.

Front

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

Back

The circumference is approximately 31.42 cm (C = 2πr = 2π(5)).

Front

What does the term 'circumference' refer to?

Back

Circumference refers to the total distance around the circle.

Front

If a circle has a circumference of 31.4 cm, what is its diameter?

Back

The diameter is approximately 10 cm (d = C/π).