Area of a Circle

Front

What is the definition of a diameter in a circle?

Back

A diameter is a line that goes from one end of the circle to the other and crosses the center point.

Front

What is the difference between a radius and a diameter?

Back

A radius is half the length of a diameter; it is the distance from the center of the circle to any point on its circumference.

Front

If the radius of a circle is 9, what is the diameter?

Back

The diameter is 18, calculated as diameter = 2 * radius.

Front

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

Back

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

Front

If the radius of a circle is 9, what is the area?

Back

The area is approximately 254.47 m², calculated as A = π(9)².

Front

What is the area of a circle with a radius of 5?

Back

The area is approximately 78.54 m², calculated as A = π(5)².

Front

How do you convert the area of a circle from square meters to square centimeters?

Back

Multiply the area in square meters by 10,000, since 1 m² = 10,000 cm².

Front

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

Back

The area is approximately 78.54 m², calculated as A = π(5)², where the radius is 5.

Front

If the area of a circle is 78.50 m², what is the radius?

Back

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

Front

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

Back

The area increases with the square of the radius; doubling the radius increases the area by a factor of four.