This document appears to be notes from multiple sessions of the structural analysis course taught by Professor Ing. Percy H. Coa Suyo. The notes cover topics like structural materials, degrees of freedom, matrix algebra for structural analysis, and the matrix method for structural analysis, including coordinate systems, stiffness equations and matrices for bars, and total stiffness matrices for frames. The document is composed primarily of repetitive text crediting Ing. Percy H. Coa Suyo as the source.