LSP: The Square–Rectangle Problem

Problem

The classic LSP violation: Square extends Rectangle. Since a square's width and height must always be equal, setting width changes height too — this breaks the Rectangle contract and surprises callers. Identify WHY this violates LSP, then redesign the shape hierarchy correctly.

Requirements

Explain the violation: show a test that passes for Rectangle but fails for Square
Fix Option A: make both Shape subclasses without inheritance between them
Fix Option B: use a read-only Shape interface (area(), perimeter()) — no setters
Show that the fixed design passes the same test for both Square and Rectangle
Apply the same thinking to Bird → FlyingBird → Penguin (another LSP violation)

Constraints

–Square must NOT extend Rectangle (or vice versa) in the final design
–Substituting Square for Shape in any caller must not break the caller

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