Measuring Circles Review

Front

What is the circumference of a circle?

Back

The distance around a circle.

Front

If my radius is 10ft, what is my diameter?

Back

20ft

Front

If my diameter is 19 inches, what is my radius?

Back

9.5 inches

Front

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

Back

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

Front

What is the area of a circle?

Back

The space contained within the circle, calculated as Area = π × radius².

Front

If the radius of a circle is doubled, how does the area change?

Back

The area increases by a factor of four.

Front

What is the relationship between diameter and radius?

Back

Diameter is twice the radius (Diameter = 2 × radius).

Front

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

Back

Radius = Circumference / (2 × π).

Front

What is π (pi)?

Back

A mathematical constant approximately equal to 3.14, representing the ratio of circumference to diameter.

Front

If the radius is 12 inches, what is the area of the circle?

Back

452.2 in².