Creating 3D Surfaces of Revolution

This example demonstrates how to create 3D surfaces of revolution from a modifiable cross section. It involves core mathematical concepts such as solids of revolution, cross-sections, 3D geometry, and function fitting. The construction uses GeoGebra commands like PointIn, IndexOf, FitPoly, Surface, Line, and objects including B, A, l2, c, b, d, A_1, B_1, C, D, degree, f, g, angle, a, l1, e, h, i, j, k. Suitable for high school and above students studying solid geometry and calculus.