The first type of reflection is on a vertical line. The most common of these is the y-axis, though you may be asked to reflect a shape in any vertical lines. [br][br]These lines will have the equation x=a, where a is the value of the point where the line passes the x-axis. The y-axis has the equation x=0 as it passes through the x-axis at 0.[br][br]Use the applet to visualise how a reflection changes if the mirror line is moved. Use the slider to move the line left and right. It starts on x=0. Try moving the points of the red triangle (or click on the shape area to move the whole shape) to see how the other changes as well.
What happens when one shape is moved closer to the mirror line?
What happens when the mirror line cuts through one of the shapes?
Are the shapes always the same distance away from the mirror line?
State the coordinates of the new quadrilateral.
(2,-1) (4,-1) (2,-3) (4,-3)
What type of quadrilateral is the shape?
State the coordinates of the new quadrilateral.
(-6,-1) (-7,-1) (-6,-4) (-7,-4)
What type of quadrilateral is the new shape?
The second type of reflection is on a horizontal line. The most common of these is the x-axis, though you may be asked to reflect a shape in any horizontal lines. [br][br]These lines will have the equation y=a, where a is the value of the point where the line passes the y-axis. The x-axis has the equation y=0 as it passes through the y-axis at 0.[br][br]Use the applet to visualise how a reflection changes if the mirror line is moved. Use the slider to move the line up and down. It starts on y=0. Try moving the points of the purple quadrilateral (or click on the shape area to move the whole shape) to see how the other changes as well.
State the coordinates of the new triangle.
What type of triangle is the shape?
Right Angled Triangle/Scalene
State the coordinates of the new quadrilateral.
(8,-4) (9,-6) (10,-4) (9,-2)
What type of quadrilateral is the shape?
The final type of reflection is on a diagonal line. You will be asked to reflect in the line y=x or y=-x.[br][br]Use the applet to visualise how a reflection changes if the points on the shape are moved. The first example shows a reflection in the line y=x. The second example is a reflection in the line y=-x.[br][br]Try moving the points of the green shape (or click on the shape area to move the whole shape) to see how the other changes as well.
State the coordinates of the new triangle.
What type of triangle is the shape?
State the coordinates of the new triangle.
[size=200]For the next few questions, you will be given the equation of the mirror line. Draw the line for each question, then reflect the shape.[/size]
Reflection: Flip a shape in a line, producing an image as if seen in a mirror.[br]Mirror Line: The line a shape if reflected over.[br]Horizontal: A line that is drawn left-to-right. These lines have equations in the form y=a.[br]Vertical: A line that is drawn top-to-bottom, running up or down. These lines have equations in the form x=a.[br]Diagonal: A line that is drawn as a upwards/downwards-facing slope. These lines commonly seen in reflection questions will have the equation y=x or y=-x.