Area and Circumference of Circles

Front

What is the formula for the circumference of a circle?

Back

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

Front

What is the formula for the area of a circle?

Back

Area = π × radius².

Front

What does the term 'diameter' refer to in a circle?

Back

The diameter is a line segment that passes through the center of the circle and connects two points on its boundary.

Front

What does the term 'radius' refer to in a circle?

Back

The radius is a line segment from the center of the circle to any point on its boundary.

Front

If the radius of a circle is 7 cm, what is the circumference?

Back

Circumference = 2 × π × 7 cm ≈ 43.98 cm.

Front

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

Back

Area = π × (5 cm)² ≈ 78.54 cm².

Front

What is the relationship between diameter and radius?

Back

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

Front

How do you find the circumference of a circle using the radius?

Back

Circumference = 2 × π × radius.

Front

What is the value of π (Pi) approximately?

Back

π (Pi) is approximately 3.14.

Front

If a circle has a circumference of 31.4 cm, what is its diameter?

Back

Diameter = Circumference / π ≈ 10 cm.