Area of circles

Front

What is the radius 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 formula for the area of a circle?

Back

The area (A) of a circle is calculated using the formula: A = πr², where r is the radius.

Front

If the diameter of a circle is 30 feet, what is the radius?

Back

The radius is 15 feet, since the radius is half of the diameter.

Front

What is the diameter of a circle with a radius of 10 miles?

Back

The diameter is 20 miles, as the diameter is twice the radius.

Front

Calculate the area of a circle with a radius of 7 inches.

Back

The area is approximately 153.94 square inches, calculated as A = π(7)².

Front

What is the relationship between diameter and radius?

Back

The diameter is twice the radius: Diameter = 2 × Radius.

Front

If a circle has an area of 78.5 square meters, what is its radius?

Back

The radius is approximately 5 meters, calculated using the formula r = √(A/π).

Front

What is π (pi)?

Back

π (pi) is a mathematical constant approximately equal to 3.14, representing the ratio of a circle's circumference to its diameter.

Front

How do you convert diameter to radius?

Back

To convert diameter to radius, divide the diameter by 2.

Front

What is the area of a circular swimming pool with a diameter of 10 feet?

Back

The area is approximately 78.54 square feet, calculated as A = π(5)².