Area and Circumference of Circles

Front

What is the definition of a circle?

Back

A circle is a shape consisting of all points in a plane that are a fixed distance from a center point.

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 twice the length of the radius and is the distance across the circle through the center.

Front

How do you calculate the circumference of a circle?

Back

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

Front

What is the value of π (pi) approximately?

Back

π (pi) is approximately 3.14.

Front

What is the formula for the area of a circle?

Back

Area = π × radius².

Front

If the radius of a circle is 6, what is the area?

Back

Area = π × 6² = 36π ≈ 113.1.

Front

If the diameter of a circle is 12, what is the radius?

Back

Radius = Diameter / 2 = 12 / 2 = 6.

Front

What is the circumference of a circle with a radius of 6?

Back

Circumference = 2 × π × 6 ≈ 37.68.

Front

What is the relationship between radius and diameter?

Back

The diameter is twice the radius.