Question

reflect the figure across the y - axis. vertices of preimage vertices of image

Explanation:

Step1: Recall reflection rule

The rule for reflecting a point $(x,y)$ across the y - axis is $(-x,y)$.

Step2: Identify pre - image vertices

First, find the coordinates of the vertices of the pre - image triangle. Let's assume the vertices of the pre - image triangle are $(x_1,y_1)$, $(x_2,y_2)$, $(x_3,y_3)$.

Step3: Apply reflection rule

For each vertex $(x_i,y_i)$ of the pre - image, the corresponding vertex of the image after reflection across the y - axis is $(-x_i,y_i)$.

Answer:

Without the actual coordinates of the pre - image vertices, we can only state the general rule. If the pre - image vertices are $(x_1,y_1)$, $(x_2,y_2)$, $(x_3,y_3)$, the image vertices are $(-x_1,y_1)$, $(-x_2,y_2)$, $(-x_3,y_3)$.