Help i dont understand the contribuary area

[LMW.dk]

Can someone explain to me why the hell did he multiply by 4,8m? I mean if it was me and i wanted to find out the the distributed load on the continuous slab then i would have multiplied 12,25 kN/m^2 with 1m = 12,25 kN/m

I'm i wrong or is the book wrong? Thanks in advance.

http://files.engineering.com/getfil...70-45f1-bb2f-ade5546024b9&file=Screenshot.jpg

http://files.engineering.com/getfil...4d3c-9fa7-aaaa85fbaa1f&file=Screenshot002.jpg

 

[wannabeSE]

You are wrong. They are calculating F, the total load on a 1m strip with a 4.5m span. This is used with the formulas in the next section to calculate moments and shears. E.G. shear = 0.4F. I can't comment on the rest. I don't know European codes and metric makes my head hurt.