Circumference and Area

Front

What is the formula for the area of a circle?

Back

Area = πr², where r is the radius of the circle.

Front

What is the value of π (pi) commonly used in calculations?

Back

π is approximately 3.14.

Front

How do you calculate the circumference of a circle?

Back

Circumference = 2πr, where r is the radius.

Front

If a circle has a diameter of 24 inches, what is its radius?

Back

Radius = Diameter / 2 = 12 inches.

Front

What is the area of a circle with a radius of 10 inches?

Back

Area = π(10)² = 314 square inches (using π ≈ 3.14).

Front

What is the circumference of a circle with a radius of 5 inches?

Back

Circumference = 2π(5) = 31.4 inches (using π ≈ 3.14).

Front

How far does a wheel with a diameter of 30 inches travel in one complete rotation?

Back

Distance = Circumference = π × Diameter = π × 30 ≈ 94.2 inches.

Front

What is the relationship between diameter and radius?

Back

Diameter = 2 × Radius.

Front

If the area of a circle is 78.5 square inches, what is the radius?

Back

Radius = √(Area/π) = √(78.5/3.14) ≈ 5 inches.

Front

What is the circumference of a circle with a radius of 7 meters?

Back

Circumference = 2π(7) ≈ 43.96 meters.