As shown in the image below, triangle ABC is reflected onto its image. Which of the following lines represents the line of reflection that maps triangle ABC onto its image?
Oy=0
O y=-2
Ox=0
X = -2

Y=2

Explanation:
By looking at the coordinate plane, we can see that triangle ABC was reflected over a horizontal line that was below it to get triangle A’B’C’.

We can find this line by looking at any two corresponding points and dividing the distance in between by 2.

For example, when we look at C and C’, there are 4 units in between. Now, we divide 4 by 2.

4/2=2

We count 2 units down from point C or two units up from point C’ and identify what line of the Y axis (because it’s a horizontal line) we land on, which is -2.

I hope this helps! Please comment if you have any questions.