Exploring the Area of a Circle

What formula is used to calculate the circumference of a circle using its diameter?

• C = πd

• C = 2πr

• A = πr^2

• A = πd^2

Which formula represents the circumference of a circle when the radius is known?

• C = πd

• C = 2πr

• A = πd^2

• A = πr^2

What is the diameter of a circle if its radius is known to be 12.5 units?

• 25 units

• 6.25 units

• 37.5 units

• 12.5 units

How do you calculate the area of a circle?

• A = πd^2

• A = πr^2

• A = 2πr

• C = πd

What is the area of a circle with a radius of 25 units?

• A = π(25)^2

• A = 2π(25)

• A = π(50)^2

• C = π(50)

Which formula is used to convert the area formula from radius to diameter?

• A = 2π(d/2)

• A = πd^2

• A = π(d/2)^2

• C = πd

If the diameter of a circle is 50 units, what is the formula to find its area?

• A = π(50)^2

• C = π(50)

• A = 2π(25)

• A = π(25)^2

If a circle's diameter is 50 units, what is its radius?

• 100 units

• 50 units

• 75 units

• 25 units

A circle has a circumference of 25.12 feet. Which formula will you use to find the radius?

• A = πd^2

• A = πr^2

• C = 2πr

• C = πd

What is the radius of a circle if its circumference is 25.12 feet?

• r = π / 25.12

• r = 2π / 25.12

• r = 25.12 / π

• r = 25.12 / (2π)