Choose **1** for numeric calculations or **2** for symbolic formulas. Select a shape, enter its dimensions and coordinates, then mark it as **Solid (+1)** or **Hole (-1)**. Add more shapes or finish when asked. The program lists each shape’s area and centroid, then calculates the total area and the composite centroid (**x̄**, **ȳ**). In symbolic mode, it shows algebraic expressions you can simplify in CAS. Type **0** or **q** when asked to quit. Use consistent units and list polygon vertices counter-clockwise for positive area.

