The flag of Afghanistan has three equal vertical stripes with colors black (#000000) on the hoist side, red (#BF0A30) in the center, and green (#009900) on the fly side. In the center of the red stripe, there is the national emblem, which consists of a mosque with a pulpit and flags on either side, below the mosque, Eastern Arabic numerals for the solar year 1298 (1919 in the Gregorian calendar, the year of Afghan independence from the UK); this central image is circled by a border consisting of sheaves of wheat on the left and right, in the upper-center is an Arabic inscription of the Shahada (the Islamic creed). The aspect ratio of the flag is 2:3.

As for geometric properties and measurements, since the flag has an aspect ratio of 2:3, if the width is 100 units, then the height would be 150 units. Each of the three colored stripes would have a width of 100/3 ≈ 33.33 units. The size and placement of the emblem can vary slightly depending on the specific rendition of the flag.