Exploring symmetry

Task
Create an applet for exploring the symmetry of a picture by reflecting a point [b][i][color=#0000ff]A [/color][/i][/b]at a symmetry line to create its image [b][i][color=#cc0000]A'[/color][/i][/b].
Explore the construction...
Instructions
Learn how to recreate the figure used above to explore the concept of symmetry.[br][br][table][tr][td]1.[/td][td][br][/td][td]Make sure that you have the [url=http://static.geogebra.org/book/intro-en/worksheets/flower.jpg]picture of the yellow flower[/url] saved on your computer before you start with the actual construction.[br][/td][/tr][tr][td]2.[/td][td][icon]/images/ggb/toolbar/mode_point.png[/icon][br][/td][td]Create a new point [i]A[/i].[br][/td][/tr][tr][td]3.[/td][td][icon]https://www.geogebra.org/images/ggb/toolbar/mode_join.png[/icon][/td][td]Construct a line of reflection through two new points by clicking twice into the [img]https://wiki.geogebra.org/uploads/thumb/a/af/Perspectives_geometry.svg/16px-Perspectives_geometry.svg.png[/img] [i]Graphics View[/i].[/td][/tr][tr][td]4.[/td][td][icon]https://www.geogebra.org/images/ggb/toolbar/mode_mirroratline.png[/icon][/td][td]Mirror point [i]A[/i] at the line to get its image [i]A’[/i].[br][b]Hint:[/b] First select point [i]A[/i] and then the line.[/td][/tr][tr][td]5.[/td][td][icon]https://www.geogebra.org/images/ggb/toolbar/mode_segment.png[/icon][/td][td]Create a segment between point [i]A[/i] and its image [i]A’[/i] by selecting both points.[/td][/tr][tr][td]6.[/td][td][icon]https://wiki.geogebra.org/uploads/thumb/e/e2/Menu-trace-on.svg/120px-Menu-trace-on.svg.png[/icon][/td][td]Turn the trace on for points [i]A[/i] and [i]A[/i]′.[br][b]Hint:[/b] Right-click [size=100](MacOS: Ctrl-click) [/size]on a point and select [i]Show Trace[/i].[br][b]Note:[/b] Whenever point [i]A[/i] is moved, it leaves a trace in the [img]https://www.geogebra.org/wiki/uploads/thumb/c/c8/Menu_view_graphics.svg/16px-Menu_view_graphics.svg.png[/img] [i]Graphics View[/i].[br][/td][/tr][tr][td]7.[/td][td][icon]https://www.geogebra.org/images/ggb/toolbar/mode_move.png[/icon][/td][td]Drag point [i]A[/i] to draw a trace.[br][b]Hint:[/b] The menu item [i]Refresh Views[/i] in the [img]https://wiki.geogebra.org/uploads/thumb/6/67/Menu-view.svg/16px-Menu-view.svg.png[/img] [i]View[/i] Menu clears all trace.[br][/td][/tr][/table]
Try it yourself...
Instructions (continued)
Learn how to recreate the figure used above to explore the concept of symmetry.[br][br][table][tr][td]8.[/td][td][icon]https://www.geogebra.org/images/ggb/toolbar/mode_image.png[/icon][/td][td]Insert the image of the yellow flower into the [img]https://www.geogebra.org/wiki/uploads/thumb/c/c8/Menu_view_graphics.svg/16px-Menu_view_graphics.svg.png[/img] [i]Graphics View[/i] using the [i]Image[/i] tool.[br][/td][/tr][tr][td]9.[/td][td][icon]https://www.geogebra.org/images/ggb/toolbar/mode_move.png[/icon][/td][td]Adjust the position of the inserted image using the [i]Move[/i] tool.[/td][/tr][tr][td]10.[/td][td][icon]https://wiki.geogebra.org/uploads/thumb/3/30/Menu-options.svg/120px-Menu-options.svg.png[/icon][/td][td]Set the image as [i]Background Image[/i] using tab [i]Basic[/i] of the the [i]Settings ([/i][img]https://wiki.geogebra.org/uploads/thumb/d/db/Stylingbar_icon_graphics.svg/16px-Stylingbar_icon_graphics.svg.png[/img] [i]Style Bar[/i]).[/td][/tr][tr][td]11.[/td][td][icon]https://wiki.geogebra.org/uploads/thumb/3/30/Menu-options.svg/120px-Menu-options.svg.png[/icon][/td][td]Reduce the [i]Opacity[/i] of the image using tab [i]Color[/i] of the [i]Settings [/i]([img]https://wiki.geogebra.org/uploads/thumb/d/db/Stylingbar_icon_graphics.svg/16px-Stylingbar_icon_graphics.svg.png[/img] [i]Style Bar[/i]).[br][br][/td][/tr][tr][td][br][/td][td][br][/td][td][b]Hint:[/b] After specifying the picture as a background image you can’t select it in the [img]https://www.geogebra.org/wiki/uploads/thumb/c/c8/Menu_view_graphics.svg/16px-Menu_view_graphics.svg.png[/img] [i]Graphics View[/i] any more. Check out the [url=https://www.geogebra.org/m/XUv5mXTm#material/a89f3vvh]options for background images[/url] for more information.[/td][/tr][/table]

Information: Exploring symmetry