In this lesson, students learn the basics of the analysis of forces engineers perform at the truss joints to calculate the strength of a truss bridge. This method is known as the “method of joints.” Finding the tensions and compressions using this method will be necessary to solve systems of linear equations where the size depends on the number of elements and nodes in the truss.

The method of joints is the core of a graphic interface created by the author in Google Sheets that students can use to estimate the tensions-compressions on the truss elements under given loads, as well as the maximum load a wood truss structure may hold (depending on the specific wood the truss is made of) and the thickness of its elements.