Area of a Circle

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

Front

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

Back

Using the formula A = πr², the area is approximately 254.47 cm².

Front

What does π (pi) represent in the context of circles?

Back

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

Front

What is the diameter of a circle?

Back

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

Front

If a circle has a diameter of 10 cm, what is its radius?

Back

The radius is half of the diameter, so the radius is 5 cm.

Front

How do you convert the radius to the area of a circle?

Back

Square the radius and multiply by π: A = πr².

Front

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

Back

The area is approximately 153.94 cm².

Front

What is the relationship between radius and diameter?

Back

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

Front

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

Back

Using the area formula, the radius is approximately 5.00 m.