task : $351$##Theoretical frameworks in civil engineering provide the backbone for understanding and applying fundamental principles to solve practical problems. Rooted in physics and mathematics, these theories encompass structural analysis, fluid mechanics, geotechnical engineering, and transportation systems. Structural theory delves into the behavior of materials under different loads, aiding in the design of resilient infrastructure. Fluid mechanics theory guides the analysis of fluid flow in pipes, channels, and open channels, crucial for hydraulic system design. Geotechnical theory explores soil mechanics, vital for foundation design and slope stability analysis. Transportation theory addresses traffic flow, optimizing road networks for efficiency and safety.