Radius or Diameter

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 the distance across the circle, passing through the center. It is twice the length of the radius.

Front

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

Back

Diameter = 2 × Radius.

Front

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

Back

Radius = Diameter ÷ 2.

Front

What is the relationship between radius and diameter?

Back

The diameter is always twice the length of the radius.

Front

If the radius of a circle is 6 m, what is the diameter?

Back

Diameter = 2 × 6 m = 12 m.

Front

If the diameter of a circle is 8 yd, what is the radius?

Back

Radius = 8 yd ÷ 2 = 4 yd.

Front

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

Back

Circumference = π × Diameter.

Front

What is the formula for the circumference of a circle using the radius?

Back

Circumference = 2 × π × Radius.

Front

What is the area of a circle in terms of radius?

Back

Area = π × (Radius)^2.