This lecture covers constrained volume problems, introducing the Lagrange multipliers method to find extrema under constraints. It explains the process step by step, from setting up the problem to finding the critical points and determining the maximum or minimum volume. The instructor demonstrates how to apply the method to various examples, emphasizing the importance of checking the necessary conditions for optimality. The lecture concludes with a discussion on the Lagrange multipliers' role in optimization and the significance of the results obtained.