Polymorphism — Simple Shape Hierarchy in Modern C++

Demonstrates runtime polymorphism with a Shape base class and concrete Circle, Square, and Quad types.

✨ Core files

Class/File	Highlights
Shape	Pure‑virtual area() / perimeter()
Circle	Stores center, radius
Square	Stores origin and side length
Quad	Four‑point arbitrary quadrilateral
allShapes	Factory & polymorphic collection demo
MainTrain	Unit‑test‑style harness

📝 Customising

• Add new shapes by inheriting Shape and overriding its virtual methods.
• Replace raw pointers with smart pointers for automatic memory handling.

⚖️ License

MIT