Circles - Radius, Diameter and Circumference

Front

What is the radius of a circle?

Back

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

Front

What is the diameter of a circle?

Back

The diameter is a line segment that passes through the center of the circle and has its endpoints on the circle. It is twice the length of the radius.

Front

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

Back

C = π·d, where C is the circumference and d is the diameter.

Front

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

Back

10 cm

Front

If the diameter of a circle is 12 inches, what is the radius?

Back

6 inches

Front

What does the symbol π (pi) represent?

Back

Pi is a mathematical constant approximately equal to 3.14, representing the ratio of the circumference of a circle to its diameter.

Front

What is the circumference of a circle with a diameter of 8 m?

Back

25.12 m

Front

How do you find the circumference of a circle using the radius?

Back

C = 2·π·r, where r is the radius.

Front

What is the relationship between diameter and radius?

Back

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

Front

What is the area of a circle?

Back

The area is the space contained within the circle, calculated using the formula A = π·r².