Question

write a rule for the reflection.
(x, y)→(□,□)

Explanation:

Step1: Observe the transformation

We see that the pre - image $\triangle ABC$ is reflected over the $x$ - axis to get $\triangle A'B'C'$.

Step2: Recall reflection rule

When a point $(x,y)$ is reflected over the $x$ - axis, the $x$ - coordinate remains the same and the $y$ - coordinate changes its sign.

Answer:

$(x,y)\to(x, - y)$