Reflect this figure across the y-axis:

Answer:
The coordinates of the image triangle will be:
Please also check the attached figure.
The green triangle represents the image triangle.
Step-by-step explanation:
We know that when we reflect a point across the y-axis, the y-coordinate remains the same but the x-coordinate reveres its sign.
Thus,
The rule of reflection of the point P(x, y) across the y-axis is:
P(x, y) → P'(-x, y)
In the attached figure, let the coordinates of the triangle are:
Using the rule of reflection across the y-axis:
P(x, y) → P'(-x, y)
Thus, the coordinates of the image triangle will be:
A(1, 1) → A'(-1, 1)
B(1, 3) → B'(-1, 3)
C(3, 3) → C'(-3, 3)
Therefore, the coordinates of the image triangle will be:
Please also check the attached figure.
The green triangle represents the image triangle.