Given
A(2,8), B(2,4), C(8,4)
A 90° clockwise about the origin has the following rules
[tex](x,y)\rightarrow(y,-x)[/tex]
Apply these rules to each of the point and we get
[tex]\begin{gathered} A\left(2,8\right)\rightarrow A^{\prime}(8,-2) \\ B\left(2,4\right)\operatorname{\rightarrow}B^{\prime}(4,-2) \\ C\left(8,4\right)\operatorname{\rightarrow}C^{\prime}(4,-8) \end{gathered}[/tex]
Drawing a diagram of the image we have the following
