Global Mapper v24.1

How to calculate width and lenght in Km using .*Hdr data

Hi  membres

I have a simple question about calculating width and lenght in km of DEM .*flt files using header data .*hdr
so i have :

ncols         1240
nrows         760
xllcorner     9,4371914430
yllcorner     34,4300096770
xdim          0,00032722957580642
ydim          0,00026934061315784

Area dimension calculated by globalMapper in Projection GeoGraphic (Lat/Lon) WGS84  is 37.29 x 22.07 km


if i use this rule :

Lenght/Width = PixelSize * ncols/nrows   that give me worng value.

1240 * 0,00026934061315784 = 0,3339823603157216

760  * 0,00032722957580642 = 0,2486944776128792

i want to know if there is any way to calculate distances ?