What are linear dimensions?

Answer 1

Linear dimensions, or linear units, measure the distance between two points. Since two points define a line, the units of distance are sometimes called "linear" units or dimensions. Some linear units are centimeters and inches, meters and feet, kilometers and miles, to name a few. Area dimensions are two-dimensional and measure area. They are often, but not always, expressed as squares of linear dimensions: square inches or inches squared (in2), square feet or feet squared (ft2), and square meters or meters squared (m2). A rectangle that is six feet long by four feet wide, for example, has an area of 24 square feet (six linear feet times four linear feet). Examples of units of area that are not a square of a linear unit are the acre and hectare. There are others. Volume dimensions are three-dimensional and are expressed as the cube of linear units. A cube that measures 2 centimeters on each edge has a volume of 2 x 2 x 2 = 8 cubic centimeters. In the context of air travel (from AlaskaAir's contract of carriage):

Maximum Outside Linear Dimensions means the sum of the greatest outside length plus the greatest outside width plus the greatest outside height.