Circle Measurements

Front

What do you need to find the circumference of a circle?

Back

You need the diameter of the circle.

Front

What is the formula to find the circumference of a circle?

Back

Circumference = π × Diameter (C = πd) or Circumference = 2 × π × Radius (C = 2πr).

Front

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

Back

31.4 cm.

Front

What is the diameter of a circle?

Back

The distance from an edge of a circle to another edge through the center.

Front

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

Back

The diameter is 10 cm.

Front

How do you find the radius if you know the circumference?

Back

Radius = Circumference / (2π).

Front

What is the circumference of a circle with a diameter of 21 feet?

Back

65.94 feet.

Front

What is the relationship between diameter and radius?

Back

The diameter is twice the radius (Diameter = 2 × Radius).

Front

If a circle has a circumference of 62.8 cm, what is the diameter?

Back

The diameter is 20 cm.

Front

What is π (pi)?

Back

π (pi) is a constant approximately equal to 3.14, used in calculations involving circles.