• halcyoncmdr@piefed.social
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    14 hours ago

    There is, but A4 isn’t the baseline, A0 is.

    A0 is 1m² with a ratio of 1:√2. Cut that in half along the larger side and you have A1, half it again and you have A2, etc. on down the line.

    The entire series maintains the same exact ratio down to A13 at 9mmx13mm.

    • surewhynotlem@lemmy.world
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      14 hours ago

      So ridiculously dedicated to metric that they didn’t think to make A0 an exponent of 2, and then designed an entire system around dividing it by 2.

      A0 should’ve been 1.024 meters.

      • f314@lemmy.world
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        13 hours ago

        You’d still get «weird» lengths in the other dimension, though. Remember, the aspect ratio has to be 1 to the root of 2 for the folding in half to work.

        Also, I don’t think 1024 would have been such an obvious number back in the late 1700’s, when this system was first thought up 😅

        There is a system of sizes where the shortest side of the base size is exactly 1 meter, though: the B system. The aspect ratio is the same as for the A sizes.