7.3.a: Radius, Diameter, Circumference

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 circumference of a circle?

Back

Circumference = π × diameter or Circumference = 2 × π × radius.

Front

What is the value of π (pi)?

Back

π (pi) is approximately 3.14.

Front

If the radius is 5ft, what is the diameter?

Back

10ft.

Front

If the diameter is 12ft, what is the radius?

Back

6ft.

Front

What is the relationship between radius and diameter?

Back

The diameter is twice the radius.

Front

If the circumference of a circle is 31.4ft, what is the diameter?

Back

10ft.

Front

What is the formula to find the radius from the circumference?

Back

Radius = Circumference / (2 × π).

Front

If the diameter is 16, what is the circumference?

Back

Circumference = π × 16 ≈ 50.24.