Radius, Diameter, Circumference Review

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 through its center, equal to twice the radius.

Front

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

Back

Diameter = 2 x Radius.

Front

What is the formula for the circumference of a circle?

Back

Circumference = 2 x π x Radius or Circumference = π x Diameter.

Front

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

Back

20 ft.

Front

If the diameter of a circle is 24 in, what is the radius?

Back

12 in.

Front

What is π (pi) approximately equal to?

Back

π is approximately equal to 3.14.

Front

If a circle has a circumference of 31.4 in, what is its radius?

Back

Radius = Circumference / (2 x π) = 5 in.

Front

What is the relationship between diameter and circumference?

Back

The circumference is π times the diameter.

Front

If the diameter of a circle is 4 ft, what is the circumference?

Back

Circumference = π x 4 ft ≈ 12.56 ft.