USEFUL DATA
To find circumference of a circle, multiply diameter by 3.1416.
 
To find diameter of a circle, multiply circumference by .31831.
 
To find area of a circle, multiply square of diameter by .7854
 
Area of a rectangle = length multiplied by breadth.  Doubling the diameter of a circle increases its area four times.
 
To find area of a triangle, multiply base by ½ perpendicular height.
 
Area of ellipse = product of both diameters times .7854.
 
Area of parallelogram = base times altitude.
 
To find side of an inscribed square, multiply diameter by 0.7071 or multiply circumference by 0.2251 or divide circumference by 4.4428.
 
Side of inscribed cube = radius of sphere times 1.1547.
 
To find side of an equal square, multiply diameter by .8862 Squared.  A side multiplied by 1.4142 equals diameter of its circumscribing circle.
 
A side multiplied by 4.443 equals circumference of its circumscribing circle.
 
A side multiplied by 1.128 equals diameter of an equal circle.
 
A side multiplied by 3.547 equals circumference of an equal circle.
 
To find cubic inches in a ball, multiply cube of diameter by .5236.
 
To find cubic contents of a cone, multiply area of base by 1/3 the altitude.
 
Surface of frustrum of cone or pyramid = sum of circumference of both ends times ½ slant height plus area of both ends.
 
Contents of frustrum of cone or pyramid = multiply area of two ends and get square root.  Add the 2 areas and multiply 1/3 altitude.
 
Doubling the diameter of a pipe increases its capacity four times.
 
A gallon of water (U.S. standard) weighs 8-1/3 lbs. and contains 231 cubic inches.
 
A cubic foot of water contains 7-1/2 gallons, 1728 cubic inches, and weighs 62-1/2 lbs.
 
To find the pressure in pounds per square inch of a column of water, multiply the height of the column in feet by .434.
 
To find capacity of tanks any size, given dimensions of a cylinder in inches, to find its capacity in U.S. gallons: square the diameter, multiply by the length and by .0034.