Convert from mkono [Africa] to line

Unit Definition (mkono [Africa])
The mkono is a traditional unit of distance in East Africa, standardized under British rule as 1/2 yard (18 inches, or 45.72 centimeters). This unit is an African version of the cubit.

Unit Definition (line)
The line is a traditional unit of distance equal to 1/12 inch (about 2.1167 millimeters). For measuring the thickness of buttons, there is also a smaller line equal to 1/40 inch (0.635 millimeter). The line is called the ligne in French, the linea in Spanish, the linie in German, and the liniya in Russian.