Question

1 rotate the figure below 90° counterclockwise. click to select polygon abcd

Explanation:

Step1: Recall rotation rule

For a 90 - degree counter - clockwise rotation about the origin, the transformation rule for a point $(x,y)$ is $(-y,x)$.

Step2: Apply rule to vertices

Let's assume the vertices of the original polygon ABCD have coordinates $(x_1,y_1),(x_2,y_2),(x_3,y_3),(x_4,y_4)$. After 90 - degree counter - clockwise rotation, the new vertices A'B'C'D' will have coordinates $(-y_1,x_1),(-y_2,x_2),(-y_3,x_3),(-y_4,x_4)$ respectively.

Step3: Plot new polygon

Plot the new vertices on the coordinate plane and connect them to form the rotated polygon A'B'C'D'.

Answer:

The green polygon A'B'C'D' is the 90 - degree counter - clockwise rotation of the original polygon ABCD.