circumference = pi*100mm
39 inches / pi = 12.4 inches
Radius is half of the diameter, so you can easily come up with a formula: L = 0.25 * pi * d2
I have a circle that measures 42" in diameter. I have to put fabric around that at a 2.5 to 1 fullness. What is the flat piece of fabric I need
circumferance
circumference/pi = diameter
circumference = pi*100mm
circumference = pi*diameter so diameter = circumference/pi = 19.1 metres.
If the diameter is known, don't bother measuring the circumference.Simply multiply the diameter by 'pi'.
Either pi times the diameter or pi times twice the radius (which is the diameter)
Circumference = (pi) x (diameter) = 14 pi = 43.9823 inches (rounded)
What is 27 X 3.14? 27 pi
Diameter of circle: 13/pi = 4.138 ft to 3 decimal places
Just over 25' ( 8 x pi)
The circumferance is found by using the formula 2(r)(pi). r stands for the radius. The diameter, which is already given in the problem, is two time radius. Therefore the only thing you really have to do is multiple the diameter= 3 inches by pi. Circumferance is 9.425 inches.
39 inches / pi = 12.4 inches
19 pi, ie 19 x 3.1415 = 59.69