L (length), W (width) and H (height) are letters representing length, width and height. In terms of engineering technology, the units in different industries are different, and the mechanical industry uses millimeters as the basic unit. Centimeter is the basic unit in civil engineering. The basic units of road and bridge engineering are meters and kilometers. In rural areas, the basic units of measurement are feet, feet and inches, while in British countries, inches are the basic units.
Representation of length, width and height
Mathematically, the lengths of three sides intersecting at a vertex are called the length, width and height of a cuboid respectively. Generally speaking, the longer side of the bottom surface is called length, the shorter side is called width, and the side perpendicular to the bottom surface is called height. Surface area of cuboid = length× width×2+width× height× 2+length× height× 2, or: surface area of cuboid = (length× width+width× height+length× height) × 2. Cuboid volume = length× width× height.
Usually, when measuring the side length of a line segment in two-dimensional space, the one with a larger length value is called length, and the one with a shorter length value (or on the side) is called width, and width is one of the measurements of length. Height is the longitudinal length of an object, that is, the distance from the bottom to the top of the object. Measuring the height of "vertical length" in three-dimensional space is also a kind of length measurement.