C9 paper size in mm

What is C9 paper size in mm ?

C9 size in mm is 40x57

The aspect ratio of an C9 paper is 1:1.43,The area of an C9 paper is 2280 mm², Perimeter of an C9 paper is 194 mm, Diagonal line of an C9 paper is 69.63 mm

Millimeter is a unit of length and a unit of rainfall, abbreviated in English as mm. 1mm=0.1cm=0.01dm=0.001m=0.000001km=1 000μm=1 000 000nm