Please solve thids problem#$?$In civil engineering, foundational theories underpin the understanding and application of structural design, materials science, and fluid mechanics. These theories encompass principles such as equilibrium, compatibility, and constitutive relations, essential for analyzing and designing structures. Moreover, theories like Euler$-$Bernoulli beam theory and plasticity theory are fundamental in structural analysis and design processes. Soil mechanics theories, including Terzaghi's principle and effective stress theory, are vital for geotechnical engineering projects. Fluid mechanics theories, such as Bernoulli's equation and Navier$-$Stokes equations, form the basis for understanding fluid behavior in hydraulic engineering. Understanding and applying these theories are crucial for solving complex engineering problems and ensuring the safety and efficiency of civil infrastructure.