Do the Math
All About Pi
Formulas with Pi
100

The circumference of a circle with a diameter of 10 inches

What is 10pi or 31.4 inches?

100

The approximate value of pi in decimal form up to two decimal places

What is 3.14?
100

The formula to find the circumference of a circle

What is pi * diameter?

200

The circumference of a circle with a radius of 2 inches

What is 4pi or 12.56 inches?

200

The number of centuries that the letter pi has been used to represent this special mathematical ratio

What is 3?

200

The formula for finding the area of a circle

What is pi * radius * radius?

300

The diameter of a circle with a circumference of 15.7 inches

What is 5 inches?

300

Pi belongs to this category of real numbers that cannot be written as simple fractions and have never-ending and never-repeating decimal forms

What are irrational numbers?

300

The formula to find the diameter of a circle given its circumference

What is circumference divided by pi?

400

The area of a circle with a radius of 4 inches

What is 16pi or 50.24 inches inches squared?

400

The APPROXIMATE value of pi in fraction form

What is 22/7?

400

The formula to find the radius of a circle given its circumference

What is circumference divided by pi and then divided by 2?

500

The area of a circle with a diameter of 6 inches

What is 9pi or 28.26 inches squared?

500

The definition of pi (hint: it's a ratio)

What is the ratio of the circumference to the diameter of a circle?

500

The formula to find the radius of a circle given its area

What is the square root of the area divided by pi?

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