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| Question 98366:  The vertices of ⌂ABC are A(-3,4) B(-1,3), C(3,-2). The triangle is rotated 90 degrees counterclockwise. Use the rotation matrix [0 -1][1 0] (please note that [1 0] is directly under [0 -1] but I do not have large enough brackets or the know-how to place it like that)to find the coordinates of C'. I hope this made sense. Thank you for helping me.
 
 Answer by stanbon(75887)
      (Show Source): 
You can put this solution on YOUR website! C(3,-2). The triangle is rotated 90 degrees counterclockwise. Use the rotation matrix [0 -1][1 0] (please note that [1 0] is directly under [0 -1] but I do not have large enough brackets or the know-how to place it like that)to find the coordinates of C'. -----------
 [0..-1]
 [1...0]
 times
 [3]
 [-2]
 C' =
 [2]
 [3]
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 You can check this out visually by plotting (3,-2),
 sketching a circle thru that point with center at
 the origin, then extimate a counter-clockwise
 rotation of 90 degrees.  Do you end up at (2,-3)?
 -----------------
 cheers,
 Stan H.
 
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