The flag of the Dominican Republic consists of a centered white cross that divides the flag into four rectangles, with blue and red rectangles on the upper left and lower right sides, respectively, and vice versa. The blue rectangle is adjacent to the hoist side of the flag. The aspect ratio of the flag is 2:3.

The colors used in the flag are defined as follows: Ultramarine blue (Pantone 286 C) and vermilion red (Pantone 186 C). The geometric properties and measurements of the flag are not specified by law, but it is commonly seen with a length of 90 cm and a width of 60 cm.

Note: As an AI language model, I cannot provide an image representation of the flag, but you can easily find it online.