Find out about shapes with curved sides and how to group them. What are 3D shapes? Learn about 3D shapes and their properties. What is tessellation? Find out how tessellation is when shapes fit ...

Two-dimensional (2D) shapes are completely flat. 2D shapes can be found printed in a book or on a website. 2D shapes have sides and corners. A rectangle has 4 straight sides and 4 corners.

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