Area of Circles

Front

What is the formula for the area of a circle?

Back

Area = π × r², where r is the radius.

Front

What does the radius of a circle represent?

Back

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

Front

If the radius of a circle is 6, what is its area?

Back

Area = π × 6² = 113.1 (approximately).

Front

What is the value of π (pi) approximately?

Back

π (pi) is approximately 3.14.

Front

How do you find the diameter of a circle if you know the radius?

Back

Diameter = 2 × radius.

Front

If the diameter of a circle is 12, what is the radius?

Back

Radius = Diameter / 2 = 12 / 2 = 6.

Front

What is the area of a circle with a radius of 12?

Back

Area = π × 12² = 452.39 (approximately).

Front

What is the relationship between radius and area in a circle?

Back

The area increases with the square of the radius.

Front

If the area of a circle is 78.54, what is the radius?

Back

Radius = √(Area / π) = √(78.54 / π) ≈ 5.

Front

What happens to the area of a circle if the radius is doubled?

Back

The area increases by a factor of four.