Can you cut a cake fairly to solve this middle school math problem?

[Whateverist]

As long as Losty used a square pan to bake her square cake and spread the frosting evenly there isn't a problem.

Y'all aren't accusing Losty of sloping the icing on unevenly, are you? I sure hope not because those kinds of accusations have consequences.

I think Chthulthuluuu's point was that if we cut it into five equal rectangular strips lengthwise then besides the issue of the frosting on the end pieces, there would also be less cake on those two end pieces.

Assuming our cutting into five equally thick rectangular strips is based on the external dimensions of the cake as measured on the frosted cake, then the thickness of the frosting itself will be contributing to the thickness of the slice for the end pieces but  not for the three middle pieces.  So, however thick the frosting is applied, that is how much cake the end pieces are not getting.  (Naturally -if I wasn't counting calories- I'd gladly trade that thin slice of cake for extra frosting.)