Question

Which of the flags has been rotated 90 degrees about the origin (point A)? Highlight the flag and label the corresponding points of the image. The final directions are in the pic below

Answer 1

When we rotate a figure 90° counterclockwise each point changes thorugh the following rule.

`(x,y)\rightarrow(-y,x)`

then, since the initial coordinates of the figure are given, apply the transformation to each point

`\begin{gathered} A(0,0)\rightarrow A^(\prime)(0,0) \\ B(3,3)\rightarrow B^(\prime)(-3,3) \\ C(5,5)\rightarrow C^(\prime)(-5,5) \\ D(7,3)\rightarrow D^(\prime)(-3,7) \\ E(5,1)\rightarrow E^(\prime)(-1,5) \end{gathered}`

If we look at the flags shown, the correct ubication of the flag is: