Circumference and Area of Circles

Front

What is the formula for the circumference of a circle?

Back

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

Front

If the diameter of a circle is 50 yards, what is the radius?

Back

Radius = diameter / 2 = 25 yards.

Front

What is the area of a circle with a radius of 6 meters?

Back

Area = π × radius² = π × 6² = 36π ≈ 113.1 m².

Front

What is the diameter of a circle if the radius is 12?

Back

Diameter = 2 × radius = 2 × 12 = 24.

Front

What is the area of a circle with a diameter of 4.5 cm?

Back

Area = π × (diameter/2)² = π × (4.5/2)² ≈ 15.9 cm².

Front

Define 'radius' in the context 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 relationship between diameter and radius?

Back

The diameter is twice the length of the radius.

Front

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

Back

Diameter = Circumference / π ≈ 10 cm.

Front

What is the area of a circle with a diameter of 10 meters?

Back

Area = π × (10/2)² = π × 5² = 25π ≈ 78.5 m².

Front

What is the circumference of a circle with a radius of 3 cm?

Back

Circumference = 2 × π × 3 ≈ 18.8 cm.