Practice 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

How do you calculate the circumference of a circle?

Back

Circumference = 2πr, where r is the radius of the circle.

Front

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

Back

The radius is the distance from the center of the circle to any point on its circumference.

Front

What is the value of π (pi) approximately?

Back

π is approximately 3.14.

Front

If the area of a circle is 50, what is the radius?

Back

r = √(Area/π) = √(50/π) ≈ 3.99.

Front

What is the relationship between diameter and radius?

Back

The diameter is twice the radius (Diameter = 2r).

Front

What is the area of a circle with a radius of 7?

Back

Area = π(7)² ≈ 153.94.

Front

What is the circumference of a circle with a diameter of 10?

Back

Circumference = π × Diameter = π × 10 ≈ 31.42.

Front

How do you convert area to radius in a circle?

Back

Use the formula r = √(Area/π).

Front

What is the significance of the symbol π in geometry?

Back

π represents the ratio of the circumference of a circle to its diameter.