Aspect ratio is the relationship between which two dimensions?

Aspect ratio is defined as the relationship between the height and width of a rectangle or a screen. This ratio is typically expressed as two numbers separated by a colon, such as 16:9, which indicates that for every 16 units of width, there are 9 units of height. Understanding aspect ratio is essential for various applications, including video production and display technologies, as it affects the composition and presentation of visual media. Height and width directly influence how content is framed and how viewers perceive the image or video in question.

The other options suggest relationships that do not represent the definition of aspect ratio. For example, length and angle do not correspond to any meaningful visual ratio in the context of screens or images. Similarly, diagonal and width, as well as diagonal and length, pertain to different measurements that are not relevant when discussing the fundamental aspect ratio of a screen or image format.