Parts of a Circle

Front

What is the diameter of a circle?

Back

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

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 circumference of a circle?

Back

The circumference is the distance around the outside of the circle.

Front

How do you calculate the diameter if you know the radius?

Back

Diameter = 2 x Radius.

Front

How do you calculate the radius if you know the diameter?

Back

Radius = Diameter / 2.

Front

What is the relationship between diameter and circumference?

Back

Circumference = π x Diameter.

Front

What is π (pi)?

Back

π (pi) is a mathematical constant approximately equal to 3.14, used in calculations involving circles.

Front

If the radius of a circle is 10 inches, what is the diameter?

Back

Diameter = 2 x 10 in = 20 in.

Front

If the diameter of a circle is 30 inches, what is the radius?

Back

Radius = 30 in / 2 = 15 in.

Front

What is the center of a circle?

Back

The center is the point that is equidistant from all points on the circumference.