Radius and Diameter

Front

What is the diameter of a circle?

Back

A straight line going from the outer edge of a circle to the other outer edge.

Front

What is the radius of a circle?

Back

A straight line going from the center point of a circle to the outer edge.

Front

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

Back

5 cm

Front

What is the relationship between diameter and radius?

Back

The diameter is twice the length of the radius.

Front

If the radius of a circle is 3 cm, what is the diameter?

Back

6 cm

Front

What is the formula to find the diameter if you know the radius?

Back

Diameter = 2 x Radius.

Front

What is the formula to find the radius if you know the diameter?

Back

Radius = Diameter / 2.

Front

If a circle has a radius of 4 inches, what is its diameter?

Back

8 inches

Front

What is the circumference of a circle with a diameter of 7 cm?

Back

Circumference = π x Diameter = 22 cm (approximately).

Front

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

Back

Area = π x (Radius)^2 = 78.5 cm² (approximately).