Editing Tangram (section)

==Pieces==
Choosing a unit of measurement so that the seven pieces can be assembled to form a square of side one unit and having area one square unit, the seven pieces are:<ref>{{Cite web|url=https://boyslife.org/hobbies-projects/projects/145561/make-a-classic-tangram-puzzle/|title=How to Make a Classic Tangram Puzzle|last=Brooks|first=David J.|date=2018-12-01|website=Boys' Life magazine|language=en|access-date=2020-03-10}}</ref>

* 2 large [[Right angle triangle|right triangles]] (hypotenuse 1, sides {{sfrac|{{sqrt|2}}|2}}, area {{sfrac|1|4}})
* 1 medium right triangle (hypotenuse {{sfrac|{{sqrt|2}}|2}}, sides {{sfrac|1|2}}, area {{sfrac|1|8}})
* 2 small right triangles (hypotenuse {{sfrac|1|2}}, sides {{sfrac|{{sqrt|2}}|4}}, area {{sfrac|1|16}})
* 1 [[Square (geometry)|square]] (sides {{sfrac|{{sqrt|2}}|4}}, area {{sfrac|1|8}})
* 1 [[parallelogram]] (sides of {{sfrac|1|2}} and {{sfrac|{{sqrt|2}}|4}}, height of {{sfrac|1|4}}, area {{sfrac|1|8}})

Of these seven pieces, the parallelogram is unique in that it has no [[reflection symmetry]] but only [[rotational symmetry]], and so its [[mirror image]] can be obtained only by flipping it over. Thus, it is the only piece that may need to be flipped when forming certain shapes.