\(\text{one way of doing this is to note that the rotation matrix for a 90 degree clockwise rotation is}\\ R=\begin{pmatrix}0 &1\\-1 &0 \end{pmatrix}\)
\(R.(x,y) = (y, -x)\\ \text{and this is simple to apply to your points}\\ \text{for example}\\ (-4,1) \to (1,4)\\ \text{I leave rotating the two other points to you}\)
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