In this series the ‘A’ size is used but in a portrait or landscape format. The long side of the rectangle is formed by taking an arc with radius of the diagonal of the square; where this meets the the extended line side of the square.
The works are available and can be purchased.
The ratio of the sides of this rectangle is √2 or 1.4142. This rectangle forms the basis of the ‘A’ size, a European standard paper size with A0 being the largest.