# Transformation - Reflection

## Reflection - Vertical or Horizontal Mirror Line - Video

### Example 1

Example 1:

In order to reflect an image when the mirror line is vertical or horizontal, we must count to the mirror line and then count the same number away from the mirror line. Pick a vertex and move around the shape until you reflected each one.

Let's start with vertex A. Vertex A is at (-4, 3) and if we count the spaces to the mirror line, it is 3 spaces to it. So now we count 3 spaces away from the mirror line and we reach A' (2, 3).

Next we go to vertex B, (-4, 1) which is 3 spaces to the line, as well. Now we count 3 spaces away from the line, and we reach B' (2, 1).

Since vertex C is on the line, C' prime will be on the line.

### Example 2

Example 2:

In order to reflect an image when the mirror line is vertical or horizontal, we must count to the mirror line and then count the same number away from the mirror line. Pick a vertex and move around the shape until you reflected each one.

Let's start with vertex A. Vertex A is at (-5, 4) and if we count the spaces to the mirror line, it is 4 spaces to it. So now we count 4 spaces away from the mirror line and we reach A' (3, 4).

Next we go to vertex B, (-5, 2) which is 4 spaces to the line, as well. Now we count 4 spaces away from the line, and we reach B' (3, 2).

Next we go to vertex C, (-2, 2) which is 1 space to the line, as well. Now we count 1 space away from the line, and we reach C' (0, 2).

### Example 3

Example 3:

In order to reflect an image when the mirror line is vertical or horizontal, we must count to the mirror line and then count the same number away from the mirror line. Pick a vertex and move around the shape until you reflected each one.

Let's start with vertex A. Vertex A is at (-2, 5) and if we count the spaces to the mirror line, it is 4 spaces to it. So now we count 4 spaces away from the mirror line and we reach A' (-2, -3).

Next we go to vertex B, (-2, 3) which is 2 spaces to the line, as well. Now we count 2 spaces away from the line, and we reach B' (-2, -1).

Next we go to vertex C, (1, 3) which is 2 spaces to the line, as well. Now we count 2 spaces away from the line, and we reach C' (1, -1).