Determine Radius and Diameter of a Circle

Front

What is the radius of a circle?

Back

The measurement from the center of a circle to an edge of the circle.

Front

What is the diameter of a circle?

Back

The measurement from one edge of the circle to the opposite edge, passing through the center.

Front

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

Back

Multiply the radius by 2.

Front

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

Back

Divide the diameter by 2.

Front

What is the relationship between radius and diameter?

Back

The diameter is twice the length of the radius.

Front

If the radius of a circle is 18, what is the diameter?

Back

36 (18 x 2).

Front

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

Back

5 in (10 in ÷ 2).

Front

What is the formula to calculate the circumference of a circle?

Back

Circumference = π x diameter.

Front

What is π (pi)?

Back

A mathematical constant approximately equal to 3.14, used in calculations involving circles.

Front

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

Back

8 (16 ÷ 2).