Question

Rotate the following ploygon 90 degrees ccw. List the new image coordinates. write the general rule.

Answer 1

The general rule for a 90° counterclockwise rotation is

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

We have to apply this rule to each point on the given table.

`\begin{gathered} A(2,3)\rightarrow A^(\prime)(-3,2) \\ B(5,3)\rightarrow B^(\prime)(-3,5) \\ C(1,5)\rightarrow C^(\prime)(-5,1) \\ D(6,5)\rightarrow D^(\prime)(-5,6) \end{gathered}`

Therefore, the new image coordinates are

A'(-3,2)

B'(-3,5)

C'(-5,1)

D'(-5,6)