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, [¨]Quadrangle¨Quadrangle / To connect vertexes(GC World : Sample ,Typical examples of GC)
Let's move A, B, C, and D.
(1)What shape will PQRS always be?
(2)What shape will PQRS be when ABCD is a rectangle?
(3)What shape of ABCD makes EFGH a rectangle?
(4)Let's think about these kinds of problems.