2D Shapes (Flat Shapes)

2D shapes are flat — they have length and width but no thickness. Types: Circle (no corners, no sides), Square (4 equal sides, 4 corners), Rectangle (2 long + 2 short sides, 4 corners), Triangle (3 sides, 3 corners). Look for shapes around you: clock=circle, window=rectangle, pizza slice=triangle, dice face=square.