What 75 linear inches?

75 linear inches refers to a measurement of length that totals 75 inches when measured in a straight line. This term is often used in contexts like luggage dimensions, where the total of length, width, and height must not exceed 75 inches for certain travel regulations. For example, a suitcase measuring 30 inches long, 20 inches wide, and 25 inches high would sum to 75 linear inches (30 + 20 + 25 = 75).