Reflections. How to reflect a shape without tracing paper on squared paper.

Here I will show you how to reflect a shape in a mirror line without using tracing paper.

All you need to do is measure the length (shortest distance) from each corner of your shape to the mirror line. Then measure the same distance on the other side of the mirror line and plot your new corner. It’s much easier to count the squares on the page rather than using a ruler to measure the lengths. Once all the new corners have been plotted, join up the corners with your ruler and you will have your reflected shape.

Let’s take a look at two examples on how to reflect shapes without using tracing paper.

Example 1

Reflect triangle ABC in the vertical mirror line.

First reflect corner A as this is the closest corner to the mirror line (so it’s the easiest corner to reflect):

Corner A is 2 squares from the mirror line so count 2 squares on the other side of the mirror line.

Now reflect the next two corners of the triangle.

Corner B is 7 squares from the mirror line so count 7 squares on the other side of the mirror line.

Corner C is 4 squares from the mirror line so count 4 squares on the other side of the mirror line.

Once you have plotted all of these corners on the other side of the mirror line join up the corners with your ruler.

Example 2

Reflect quadrilateral ABCD in the mirror line.

Start with corner A is this is the easiest to reflect. Since corner A is on the mirror line corner A will stay in this position on the reflected shape.

Corner B is 3 squares from the mirror line so count 3 squares on the other side of the mirror line.

Corner C is 6 squares from the mirror line so count 6 squares on the other side of the mirror line.

Corner D is 4 squares from the mirror line so count 4 squares on the other side of the mirror line.

Now that all the corners have been reflected join up the corners with the ruler. Make sure you join up the correct corners. Remember, that your reflected shape will look like the original shape but flipped over.

So reflecting shapes without tracing paper is much more accurate than using tracing paper. Tracing paper is only useful when the shapes don’t have straight edges. If all the sides are straight then stick with this method.