Understanding Circles: Radius and Diameter Flashcard

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

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

Back

10 inches

Front

If the radius of a circle is 9 meters, what is the diameter?

Back

18 meters

Front

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

Back

14 meters

Front

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

Back

8 inches

Front

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

Back

5 cm

Front

How do you calculate the diameter from the radius?

Back

Multiply the radius by 2.

Front

How do you calculate the radius from the diameter?

Back

Divide the diameter by 2.

Front

What is the relationship between radius and diameter?

Back

The diameter is always twice the length of the radius.