I don't think there is one. At least from what I can gather, this isn't quite a proof that the diagonal of a unit square has length √2. The tablet tells us tha

I don't think there is one. At least from what I can gather, this isn't quite a proof that the diagonal of a unit square has length √2. The tablet tells us that the Babylonians knew the length was √2, but it doesn't tell us how they knew, or how they could prove they were right.