Question

reflect the figure over the line y = 1. plot all of the points of the reflected figure. you may click a plotted point to delete it.

Explanation:

Step1: Recall reflection rule

For a point $(x,y)$ reflected over the line $y = k$, the new - point $(x,y')$ is given by the formula $y'=2k - y$. Here $k = 1$.

Step2: Assume vertices of the triangle

Let the vertices of the original triangle be $(x_1,y_1),(x_2,y_2),(x_3,y_3)$. For each vertex, we use the formula $y'_i=2\times1 - y_i=2 - y_i$ while keeping the $x$ - coordinate the same. For example, if a vertex is $(x,y)$ of the original triangle, its reflection over $y = 1$ is $(x,2 - y)$.

Answer:

To plot the reflected figure, find the reflection of each vertex of the original triangle using the rule $(x,y)\to(x,2 - y)$ and then connect the reflected points.