Understanding Circles: Area and Circumference

What is the formula for the area of a circle?

• pi / radius^2

• 2 * radius / pi

• pi * radius^2

• 2 * pi * radius

What does pi approximately equal to?

• 2.718

• 3.14

• 3.14159

• 2.18

How do you calculate the circumference of a circle?

• radius / pi

• 2 * pi * radius

• pi / 2 * radius

• pi * radius^2

What is the value of pi used in most calculations?

• 2.718

• 22/7

• 3.14

• 3.14159

What is the correct way to express the area of a circle in terms of pi?

• Radius squared * pi

• Pi / radius squared

• 2 * radius * pi

• Radius * pi

If a circle has a radius of 5 feet, what is its area?

• 78.54 square feet

• 31.42 square feet

• 10 pi square feet

• 25 pi square feet

If a circle has a radius of 5 feet, what is its circumference?

• 31.42 feet

• 10 pi feet

• 78.54 feet

• 25 pi feet

Why is the circumference not squared in its unit of measurement?

• Because it represents length

• Because it represents density

• Because it represents area

• Because it represents volume

If a circle has a radius of 4 feet, what is its area?

• 50.27 square feet

• 16 pi square feet

• 8 pi square feet

• 25.13 square feet

If a circle has a radius of 4 feet, what is its circumference?

• 8 pi feet

• 16 pi feet

• 50.27 feet

• 25.13 feet