English: Derivation of 16:9 aspect ratio used in high-definition television by CMG Lee. The upper figure shows rectangles with aspect ratios 4:3 (blue), 5:3 (cyan), 1.85 (green), 2.2 (yellow) and 2.35 (red) with the same area, A, and rectangles with aspect ratio 16:9 that covers (black) or is part of (grey) all the previous rectangles. The lower figure shows how this aspect ratio is obtained by considering the two most extreme rectangles. m and n are multipliers to maintain their respective aspect ratios and areas.