Yah, i was being lazy... and even though I'm a Canadian which, like Belgium, is metric, I gave the measurements in inches. " is the sign for inches. ' is for feet.
What unit does " refer to? As far as I know it's seconds, which could define a corner but which seems rather unpractical (and extremely small).
So, This works out to
Side: 16.5" ~ 42cm (I just remesured)
Left: 14 inches - ~35cm
Right: 14 inches - ~35cm