Exploring Circumference and Area of a Circle

What is the formula for the circumference of a circle?

• C = 2 * Pi * radius

• C = Pi * diameter

• C = diameter / Pi

• C = radius * Pi

What is the value of Pi used in the calculations?

• 3.14159

• 3.14

• 3.1

• 3

If the diameter of a circle is 20 cm, what is the circumference?

• 63.4 cm

• 60 cm

• 64 cm

• 62.8 cm

How do you calculate the diameter if you know the radius of the circle?

• None of the above

• Multiply the radius by Pi

• Divide the radius by 2

• Multiply the radius by 2

If the radius of a circle is 8 units, what is the circumference using Pi as 3.14?

• 50.24 units

• 50 units

• 48 units

• 52 units

What operation do you perform to find the diameter when you know the circumference?

• Subtract Pi

• Add Pi

• Divide by Pi

• Multiply by Pi

If the circumference of a circle is 68.5 units, what is the diameter?

• 20 units

• 21.8 units

• 22 units

• 23 units

How do you find the radius if you have the diameter?

• Add Pi to the diameter

• None of the above

• Divide the diameter by 2

• Multiply the diameter by 2

If the diameter calculated from the circumference is 18 units, what is the radius?

• 9 units

• 36 units

• 18 units

• 8 units

What is the correct formula to find the radius from the circumference?

• Radius = Circumference / (Pi * 2)

• Radius = Circumference / (2 * Pi)

• Radius = Circumference * Pi

• Radius = Circumference / Pi