A length is a standard unit of measurement used to measure distance. The exact length of a length can depend on the context in which it is being used, with different lengths being assigned to different types of measurements. For example, when talking about swimming pools, one length would typically be equal to one lap around the pool or 25 meters. Therefore, four lengths would equate to 100 meters (4 x 25m). Similarly, when discussing horses entering competitions such as horse racing and showjumping, one length is generally considered as 8 feet (or 2.44 metres). Therefore 4 lengths for this type of application would be equal to 9.76 metres (4 x 2.44m). Ultimately it depends on what type of measurement you are referring too as the definition and size per “length” does vary depending upon context; however most commonly 4 lengths will usually equate to around 10-100 meters worth of distance depending on the situation at hand!