Question: What is the Aspect ratio of a 1080p monitor?
Context: 480p is the shorthand name for a family of video display resolutions.  The "p" stands for progressive scan, i.e. non-interlaced.  The "480" denotes a vertical resolution of 480 pixels, usually with a horizontal resolution of 640 pixels and aspect ratio (480 × ⁄ = 640) or a horizontal resolution of 854 or less (848 should be used for mod16 compatibility) pixels for an approximate aspect ratio (480 × ⁄ = 853.3 ).  Since a pixel count must be a whole number, in Wide VGA displays it is generally rounded up to 854 to ensure inclusion of the entire image.  The frames are displayed progressively as opposed to interlaced.  480p was used for many early Plasma televisions.  Standard definition has always been a 4:3 aspect ratio with a pixel resolution of 640 × 480 pixels.  Mini-DV, DVCAM, DV footage is recorded at 29.97 frames per second in this standard definition as seen on DV tapes. High-Definition Versatile Disc (HVD) is an Asian standard of advanced high-definition technology originally developed in China by AMLogic Inc., for high-definition video.  The format resolutions support 720p, 1080i, or 1080p on version 1 discs.  Version 2 of the format added high-resolution beyond the standard fare of HD for use on non-TV monitors that support higher resolutions, up to 1080p. The aspect ratio of an image describes the proportional relationship between its width and its height.  It is commonly expressed as two numbers separated by a colon, as in "16:9".  For an "x":"y" aspect ratio, no matter how big or small the image is, if the width is divided into "x" units of equal length and the height is measured using this same length unit, the height will be measured to be "y" units. For the table below, SAR (storage aspect ratio) is based solely on pixel count.  It does not take into account PAR (pixel aspect ratio, pixels may be non-square) and thus the DAR (display aspect ratio, the aspect ratio of the actual image that is displayed) may differ. The Nikon D5100 is a 16.2-megapixel DX-format DSLR F-mount camera announced by Nikon on April 5, 2011.  It features the same 16.2-megapixel CMOS sensor as the D7000 with 14-bit resolution, while delivering Full HD 1080p video mode at either 24, 25 or 30fps.  The D5100 is the first Nikon DSLR to offer 1080p video at a choice of frame rates; previous Nikon DSLRs that recorded 1080p only did so at 24 fps.  It replaces the D5000 and is replaced by the D5200. Variable-geometry turbochargers (VGTs), (also known as variable nozzle turbines/VNTs), are a family of turbochargers, usually designed to allow the effective aspect ratio (A:R) of the turbo to be altered as conditions change.  This is done because optimum aspect ratio at low engine speeds is very different from that at high engine speeds.  If the aspect ratio is too large, the turbo will fail to create boost at low speeds; if the aspect ratio is too small, the turbo will choke the engine at high speeds, leading to high exhaust manifold pressures, high pumping losses, and ultimately lower power output.  By altering the geometry of the turbine housing as the engine accelerates, the turbo's aspect ratio can be maintained at its optimum.  Because of this, VGTs have a minimal amount of lag, have a low boost threshold, and are very efficient at higher engine speeds.  VGTs do not require a wastegate. (1920x1080 px; also known as full HD or FHD and BT.709) is a set of HDTV high-definition video modes characterized by 1080 horizontal lines of vertical resolution; the "p" stands for progressive scan, "i.e." non-interlaced.  The term usually assumes a widescreen aspect ratio of , implying a resolution of 2.1 megapixels.  It is often marketed as full HD, to contrast 1080p with 720p resolution screens. In aeronautics, the aspect ratio of a wing is the ratio of its span to its mean chord.  It is equal to the square of the wingspan divided by the wing area.  Thus, a long, narrow wing has a high aspect ratio, whereas a short, wide wing has a low aspect ratio. Digital component video is defined by ITU-R BT.601 (formerly CCIR 601) standard and uses the Y'CbCr colorspace.  Like Analog Component Video it gets its name from the fact that the video signal has been split into two or more components, that are then carried on multiple conductors between devices.  Digital component video is slowly becoming popular in both computer and home-theatre applications.  Component video is capable of carrying signals such as 480i, 480p, 576i, 576p, 720p, 1080i and 1080p, although many TVs do not support 1080p through component video. 5K resolution is horizontal resolution of about 5,000 pixels.  The most common 5K resolution is 5120 × 2880, which has an aspect ratio of 16:9 and is about 14.7 million pixels (just over seven times as many pixels as 1080p Full HD).  This resolution is typically used in computer monitors, and is not a standard format in digital television and digital cinematography, which feature 4K resolutions and 8K resolutions.
Answer: 16:9