## Most recent change of A4Paper

Edit made on March 05, 2019 by ColinWright at 16:28:00

Deleted text in red / Inserted text in green

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[[[>40 IMG:A4paper.png ]]]
All A grade sheets of paper are rectangles whose sides are in the ratio EQN:\sqrt{2}:1.
All A grade sheets of paper are rectangles whose sides are in the ratio $\sqrt{2}:1.$

The area of an A0 sheet is 1 square metre.

Folding an 'Ax' sheet of paper in half produces an 'A(x+1)' sheet.

Therefore, the area of an 'Ax' sheet of paper is EQN:(\frac{1}{2})^x square metres.
Therefore, the area of an 'An' sheet of paper is $(\frac{1}{2})^n$ square metres.

The actual dimensions of A4 are 297 mm x 210 mm. We can compute the dimensions as EQN:\frac{250\sqrt2}{sqrt(\sqrt2)} mm and EQN:\frac{250}{sqrt(\sqrt2)} mm that's 297.3017 ... mm and 210.2241 ... mm. Very, very close.
The actual dimensions of A4 are 297 mm x 210 mm. We can compute the dimensions
as $\frac{250\sqrt2}{sqrt(\sqrt2)}$ mm and $\frac{250}{sqrt(\sqrt2)}$ mm that's
297.3017 ... mm and 210.2241 ... mm. Very, very close.

The ratio of sides is an irrational number, just as for a golden rectangle.