This applet investigates mathematical reflections, and is one in series on transformation of shapes. Learn how to draw reflections, and find the line of reflection (mirror, bilateral) symmetry using a perpendicular bisector.
Author and programmer: Ron Barrow
UK Years 7-11, KS3, KS4, Higher and Foundation GCSE Mathematics - Geometry, Shape and SpaceTweet
How to Use this Applet
At the start you will see a shape in the centre (the object) and the same shape in a different colour (the image) some distance away from it. The image is a reflection of the object, in the line y = x. At any time you can:
• change the shape of the object by clicking and dragging its red dots. This will change the image as well.
• change the line of reflection by clicking and dragging its red dots. This will change the image while the object stays still.
• show or hide the line of reflection by ticking or unticking the "Line" box.
• show or hide the equation of the line of reflection, if it is visible, by ticking or unticking the "Equation" box.
• turn on or off a connecting line (ray) by ticking or unticking its box ("Ray").
• turn on or off the Perpendicular Bisector of the ray by ticking or unticking its box ("Perp. Bisector") - I'll leave you to discover why!
• turn on or off the axes or the gridlines by ticking or unticking the "Axes" or "Gridlines" boxes.
• decide whether you want filled solid shapes or empty outlines by ticking or unticking the "Shapes filled" button.
• return to the start position by clicking the "Reset" button at the top of the screen.
There is a great deal of investigation to be done using this applet. Play around. Enjoy yourself as you learn.