$....$Civil engineering theory involves fundamental principles in structural mechanics, materials science, fluid mechanics, geotechnical engineering, and construction management. Key theories include stress and strain analysis, equilibrium equations, Mohr's circle, and fluid flow principles. Long questions often address theoretical aspects: $1)$ Explain the principles of stress and strain analysis in materials. $2)$ Discuss the application of fluid mechanics principles in hydraulic structures. $3)$ Analyze the behavior of soil under different loading conditions using geotechnical theories. $4)$ Describe the mathematical models behind structural mechanics principles in bridge design. $5)$ Evaluate the role of construction management theories in project planning and execution.