Estimators use linear feet for items priced by length, such as pipe, conduit, wall base, handrail, curb and wall pads.
Example: a gym wall has 40 linear feet of wall pad. If each pad is 2 ft wide, the wall needs 20 pads.
Measure along the centerline of the item and follow each turn. Check the drawing scale on every sheet before you measure, because enlarged plans use a different scale. Convert length to pieces using the product size. Then add waste for cuts as your trade requires.