Circumference of a Circle

The Circumference of a Circle

The circumference of a circle is slightly more than three times as long as its diameter. The exact ratio is called π. The constant, sometimes written pi, is approximately equal to 3.14159 or . Actually this number is unlike any other number that you have met so far. It cannot be written exactly as a fraction or as a decimal. 

This number has been represented by the Greek letter "π" since the mid-18th century and now you can also find a π button on your calculator. 

From your investigation we can conclude that that the Circumference of a Circle can be found by using one of these two formulae:

                                C = πd or C = 2πr                      

Move to next topic ➡  Arc of Circle