Hey there! I'm happy to help!
It appears that the transformation from shape 1 to shape 2 is a 90 degree clockwise rotation about the origin. It is clockwise because 1 moves to 2 in the direction of a clock, and since it moves 1 quadrant it is 90 degrees.
Look at the corner of shape 1 at (-1,3). If you rotate the shape, the new point is at (3,1). This follows the formula that shows a 90 degree clockwise rotation: (x,y)⇒(y,-x).
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