Flag of Malaysia — construction sheet
Own work. Dimensions of the flag, stripes, canton, and star, as well as partial dimensions of the crescent are obtained from a government drawing in the publication: Symbols of National Greatness.  The government has issued several different versions of the drawing over the years; all appear to be missing two bits of important information:

Radius and/or diameter of the inner arc of the crescent.
Centre point of the inner arc of the crescent.
The drawing in the publication listed above is not sufficiently accurate to take measurements from. Therefore a measurement of the diameter of the inner arc has been taken from an an older government drawing.  The older drawing although done by hand is done to scale with a reasonably degree of accuracy.  The centre point of the arc has been calculated using a combination of the measured arc diameter and the labeled width of the crescent.
MapGrid