4 * pi = 12.566370614359172953850573533118
But just round it off to 12.57 unless otherwise directed.
pi = 3.142... It is a mathematical constant sometimes approximated as 22/7 but if your calculator has a pi function, use it. On my calculator i would type (4) (*) (pi) (=)
Pi looks like a squiggly line ~ with two curved lines beneath it, if you are not sure what it is.
Chat with our AI personalities
Take "pi" times the diameter of the circle. Pi = 3.14159 (ALWAYS) If circle has a diameter of 10cm, circumference 31.41cm If circle has a radius of 2inches, the circumference is 12.57 inches. (radius = 2, diameter = 4)
circumference formula is pi(diameter) diameter is 2(radius) radis=4; diameter=2(4)=8 pi(8)=circumference of the circle...this is the EXACT answer plug it into a calculator and you will get 25.1327412287 your welcome ;)
The circumference of a circle with a diameter of 25 is: 78.54
If the diameter of a circle is 9 the circumference is: 28.3
If a circle has a diameter of 2.25, the circumference is: 7.069