How to draw a figure with central symmetry in mathematics?

As shown in the figure, △ABC and point O are known. Expand CO to c' so that c' o = co; Expand B'O to b to make bo = B' o；; Extend AO to a' so that A'O=AO. Just connect A'B'C at three o'clock. _ Hope to adopt (it is very important to use your hands and brains more-you can ask the teacher if you don't understand)

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