When you look in a mirror in the morning, what do you notice?
How far away from the mirror does your reflection appear to be? It's the same distance from the mirror as you are. If you get closer, so does your reflection.
What happens if you raise your right hand? Your reflection appears to raise it's left hand, it's always the opposite way round.
In Maths, you have to be able to use these observations to reflect a shape.
What are the rules?
1) A reflection will be the same distance away from the mirror line as the original object is.
2) Any reflected shape will be the other way around.
Example 1: Reflecting a point.
Reflect the point a in the y-axis
Step 1: Identify the mirror line and count how far away it is from the shape.
The y-axis is the main line going up, we can then see that this is two squares away from the point we are reflecting.
When we are counting to the morror line, we always count at 90° to the line.
Step 2: Count the same distance from the other side.
Step 3: Draw and label the point.
When we are drawing reflections, we need to be able to tell between the original and the reflected shape.
To do this we use dashes.
If the original is a, the reflection is a'.
Example 2: Reflect shape a in the line y = 1.
Step 1: Identify the mirror line.
A lot of the time, you will be told to reflect in one of the axes. In this question you have to reflect in the line y = 1.
Remember that the line y = 1 will be a horizontal line that goes through the y - axis at 1.
Step 2: Reflect each of the corner points (the vertices) in the new mirror line.
We just do this the same way that we did before, there's just more of them.
Step 3: Join up the points and label the shapes.