The Radius of a Circle

Front

What is the definition of the radius of a circle?

Back

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

Front

How is the radius related to the diameter of a circle?

Back

The radius is half of the diameter. The formula is: r = d/2.

Front

If the radius of a circle is 4, what is the diameter?

Back

The diameter is 8, calculated using the formula d = 2r.

Front

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

Back

The area A of a circle is given by the formula A = πr².

Front

What is the formula for the circumference of a circle in terms of the radius?

Back

The circumference C of a circle is given by the formula C = 2πr.

Front

If the radius of a circle is 2, what is the area?

Back

The area is 12.57, calculated using A = π(2)².

Front

If the radius of a circle is 1, what is the circumference?

Back

The circumference is approximately 6.28, calculated using C = 2π(1).

Front

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

Back

If the radius is doubled, the area increases by a factor of four.

Front

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

Back

The area of a sector is proportional to the square of the radius.

Front

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

Back

You can find the radius using the formula r = √(A/π).