√139 = 11.79 (4sf)
but, √369.83 = 19.231 (5sf)
C++ has nothing to do with pixels. Your question may be related with 'Windows programming' or 'DOS programming' or 'X Window System programming'.
Last night when the market closed, it was worth almost 50 cents, but more than 49 cents,U.S.
This kind of conversion cannot be made. A pound of something refers to its weight. A gallon of something refers to its volume. If you want to know how many pounds of water there are in a one gallon container, the answer is 8.35 pounds. If you want to know how many pounds of liquid mercury would fit in a gallon jug, that would be about 112.85 pounds. A gallon of milk weighs approximately 8 pounds.
The conversion requires you to know the specific gravity of the liquid in question. Multiply that by 8.33.