Points A(-4,1), B(-1,4) and C(-1,1) are the vertices of triangle ABC. What will be the coordinates of the image of point A if triangle ABC is rotated 90 degrees clockwise about the origin?
one way of doing this is to note that the rotation matrix for a 90 degree clockwise rotation isR=(01−10)
R.(x,y)=(y,−x)and this is simple to apply to your pointsfor example(−4,1)→(1,4)I leave rotating the two other points to you
+1245 
