Editing Truss (section)

===Planar truss===
[[File:Roof truss 2.jpg|thumb|Roof truss]]
A planar truss lies in a single [[Plane (mathematics)|plane]].<ref name="hibbeler"/> Planar trusses are typically used in parallel to form roofs and bridges.<ref>{{Cite book |url=https://books.google.com/books?id=fhJADQAAQBAJ&q=Planar+trusses+are+typically+used+in+parallel+to+form+roofs+and+bridges&pg=PA128 |title=Introduction to Solid Mechanics: An Integrated Approach |last1=Lubliner |first1=Jacob |last2=Papadopoulos |first2=Panayiotis |date=2016-10-23 |publisher=Springer |isbn=9783319188782 |language=en}}</ref>

The depth of a truss, or the height between the upper and lower chords, is what makes it an efficient structural form. A solid [[girder]] or [[Beam (structure)|beam]] of equal strength would have substantial weight and material cost as compared to a truss. For a given [[Span (engineering)|span]], a deeper truss will require less material in the chords and greater material in the verticals and diagonals. An optimum depth of the truss will maximize the efficiency.<ref name="meriman">{{cite book |last=Merriman |first=Mansfield |title=American Civil Engineers' Pocket Book |orig-year=192 |url=https://books.google.com/books?id=AUVIAAAAIAAJ |access-date=2008-08-16 |year=1912 |publisher=J. Wiley & Sons |location=New York |page=785 |quote=The Economic Depth of a Truss is that which makes the material in a bridge a minimum.}}</ref>