At the beginning of the lecture a worked problem involving superposition is presented. Some remarks on the lab experiment are made regarding the method of solving the problems. The major part of the lecture concerns ways to extend the 1D solutions for unsteady heat conduction using principles of orthogonal conduction and ways to deal with perfectly insulated boundaries.  A wide variety of 2D and 3D shapes can be represented by combining the solutions for 1D unsteady heat conduction.