The document discusses tessellations, which are shapes that can cover a surface without gaps by repeating copies of the shape. Common shapes like squares and triangles can tessellate, but unusual shapes or combinations of different shapes may also tessellate. Specific tessellation shapes are discussed, including pentominoes (shapes made of 5 connected squares) and 7-pin polygons. Instructions are provided for creating original tessellations by modifying basic shapes that tessellate.