Flag of the United States — construction sheet
Own work. Geometry from Flag and Seal, Seat of Government, and the States.

On this construction sheet, the width of the flag has been assigned a unitless value of 3900 which is not part of the government specification.  The number 3900 has been chosen because it allows all given dimensions to be expressed as whole numbers.  It may be noted that the value of 3900 is also used internally within the SVG encoding of File:Flag of the United States.svg.
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