Table AII-11.--Circles
Circumference of a circle = diameter 3.1416
Diameter of a circle = circumference .31831
Area of a circle = the square of the diameter 0.7854
Surface of a ball (sphere) = the square of the diameter 3.1416
Side of a square inscribed in a circle = diameter 0.70711
Diameter of a circle to circumscribe a square = one side 1.4142
Cubic inches (volume) in a ball = cube of the diameter 0.5236
When doubled, the diameter of a pipe increases its capacity four times
Radius of a circle 6.283185 = circumference
Square of the circumference of a circle 0.07958 = area
1/2 circumference of a circle 1/2 its diameter = area
Circumference of a circle .159155 = radius
Square root of the area of a circle 0.56419 = radius
Square root of the area of a circle 1.12838 = diameter
AII-12