Area and Circumference of a Circle

Front

What is the formula to calculate the area of a circle?

Back

Area = πr², where r is the radius.

Front

What is the formula to calculate the circumference of a circle?

Back

Circumference = 2πr or Circumference = πd, where r is the radius and d is the diameter.

Front

What does the term 'radius' mean in relation to a circle?

Back

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

Front

What does the term 'diameter' mean in relation to a circle?

Back

The diameter is the distance across the circle through its center, equal to twice the radius.

Front

If the radius of a circle is 7 inches, what is the diameter?

Back

Diameter = 2 * radius = 2 * 7 = 14 inches.

Front

Calculate the area of a circle with a radius of 3 inches.

Back

Area = π(3)² ≈ 28.27 in².

Front

Calculate the circumference of a circle with a radius of 10 inches.

Back

Circumference = 2π(10) ≈ 62.83 in.

Front

What is the relationship between the radius and diameter of a circle?

Back

The diameter is always twice the radius.

Front

If a circle has a diameter of 20 inches, what is its radius?

Back

Radius = Diameter / 2 = 20 / 2 = 10 inches.

Front

What is the approximate value of π (pi)?

Back

π (pi) is approximately 3.14.