Carta APK

With paper size indicates the size (length to height) of a sheet of paper. The international standard paper size, the ISO 216, is based on the German standard DIN ISO 476. The formats are all based on a single aspect ratio of square root of 2. The base format is a sheet of paper of 1 m² (A0). Formats beyond (A1, A2, A3 and so on) are obtained simply by cutting in half the paper on the longer side. The format is the most used and known A4 (210 × 297 mm). In addition to the series A, there is a less common B series together with a series C. The area of ​​the sheets of Series B is a geometric mean of sheets of A and series C is used almost exclusively for envelopes and is defined in the standard ISO 269.