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.