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First, we found the initial two lines of symmetry, as shown on the example, which would split the paper in half. We drew them on the same piece of paper. Then we found the diagonals, which were not symmetrical when we folded them, but still split the paper in half. We then noticed that between each available gap we could draw a line splitting the gap(which was triangular) in half, going through the centre point. Using this, we worked out that each gap could be halved again and again, which led us to conclude that an A4 piece of paper can be split in half infinite times using a straight line going through the centre point.