The answer to this question is found by following the standard formula to find the circumference of a circle. The circumference is found by multiplying the diameter by Pi (π), which is 3.14 to the nearest 2 decimal places.
• Circumference = π x diameter
• Circumference = 3.14 x 10cm
• Circumference = 31.4cm
This formula is easily applicable whatever the diameter is. If the diameter was 25cm, for instance, we can repeat the formula:
• Circumference = 3.14 x 25cm
• Circumference = 78.5 cm
As well as working out the circumference of a circle, it is also possible to calculate the area of a circle by using π.
Area = π x r squared (Pi x radius x radius)
Therefore, for a circle with a diameter of 10cm, we simply halve the diameter to get the radius (5cm)
• Area = π x radius x radius
• Area = 3.14 x 5cm x 5cm
• Area = 78.5cm
Pi can be expressed more precisely than just to 2 decimal places if you wish. Pi to ten decimal places is 3.1415926535. π has actually been calculated by computers to more than one trillion digits. However, even at its most advanced levels, it is rarely practical or useful to ever apply Pi to more than twelve decimal places.
Pi is a mathematical constant with a value that is the ratio of any circle's circumference to its diameter. Pi is used is many different mathematical formulas - it is one of the most important mathematical constants. It is an irrational number, which means it cannot be expressed exactly as a fraction. Its decimal representation never ends.