∆ABC is translated 2 units down and 1 unit to the left. Then it is rotated 90° clockwise about the origin to form ∆A′B′C′. The coordinates of vertex A′ of ∆A′B′C′ are
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The coordinates of vertex B′ of ∆A′B′C′ are
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The coordinates of vertex C′ of ∆A′B′C′ are
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