Create an interactive figure that allows your students to explore the angle sum in a triangle.
[table] [tr] [td]1.[/td] [td][icon]/images/ggb/toolbar/mode_polygon.png[/icon][/td] [td]Create a triangle [i]ABC[/i] with counter clockwise orientation.[/td][/tr] [tr] [td]2.[/td] [td][icon]/images/ggb/toolbar/mode_angle.png[/icon][/td] [td]Create the angles [i]α[/i], [i]β[/i] and [i]γ[/i] of triangle [i]ABC[/i].[/td][/tr] [tr] [td]3.[/td] [td][icon]/images/ggb/toolbar/mode_slider.png[/icon][/td] [td]Create a slider for angle [i]δ[/i] with Interval 0 ̊ to 180 ̊ and [i]Increment[/i] 10 ̊.[/td][/tr] [tr] [td]4.[/td] [td][icon]/images/ggb/toolbar/mode_slider.png[/icon][/td] [td]Create a slider for angle [i]ε[/i] with Interval 0 ̊ to 180 ̊ and [i]Increment[/i] 10 ̊.[/td][/tr] [tr] [td]5.[/td] [td][icon]/images/ggb/toolbar/mode_midpoint.png[/icon][/td] [td]Create midpoint [i]D[/i] of segment [i]AC[/i] and midpoint [i]E[/i] of segment [i]AB[/i].[/td][/tr] [tr] [td]6.[/td] [td][icon]/images/ggb/toolbar/mode_rotatebyangle.png[/icon][/td] [td]Rotate the triangle around point [i]D[/i] by angle [i]δ[/i] (setting [i]clockwise[/i]).[/td][/tr] [tr] [td]7.[/td] [td][icon]/images/ggb/toolbar/mode_rotatebyangle.png[/icon][/td] [td]Rotate the triangle around point [i]E[/i] by angle [i]ε[/i] (setting [i]counterclockwise[/i]).[/td][/tr] [tr] [td]8.[/td] [td][icon]/images/ggb/toolbar/mode_move.png[/icon][/td] [td]Move both sliders [i]δ[/i] and [i]ε[/i] to show 180 ̊.[/td][/tr] [/table]
[table] [tr] [td]9.[/td] [td][icon]/images/ggb/toolbar/mode_angle.png[/icon][/td] [td]Create angle ζ using the points [i]A’C’B’.[/i][/td][/tr] [tr] [td]10.[/td] [td][icon]/images/ggb/toolbar/mode_angle.png[/icon][/td] [td]Create angle η using the points[i] C'[sub]1[/sub]B'[sub]1[/sub]A'[sub]1[/sub][/i].[/td][/tr] [tr] [td]11.[/td] [td][img]https://wiki.geogebra.org/uploads/thumb/d/db/Stylingbar_icon_graphics.svg/32px-Stylingbar_icon_graphics.svg.png[/img][/td] [td]Enhance your construction using the [i]Stylebar[/i].[br][u]Hint[/u]: Congruent angles should have the same color.[/td][/tr] [tr] [td]12.[/td] [td][icon]/images/ggb/toolbar/mode_text.png[/icon][/td] [td]Create dynamic text displaying the interior angles and their values (e.g. enter [code]α = [/code]and select α from the list of objects on tab [img]https://wiki.geogebra.org/uploads/thumb/4/4e/Geogebra-logo-elipse.svg/16px-Geogebra-logo-elipse.svg.png[/img] of the [i]Advanced [/i]section).[/td][/tr] [tr] [td]13.[/td] [td][icon]https://wiki.geogebra.org/uploads/thumb/4/40/Menu_view_algebra.svg/120px-Menu_view_algebra.svg.png[/icon][/td] [td]Calculate the angle sum using [code]sum = α + β + γ[/code].[/td][/tr] [tr] [td]14.[/td] [td][icon]/images/ggb/toolbar/mode_text.png[/icon][/td] [td]Insert the angle sum as a dynamic text: [code]α + β + γ =[/code] and select [i]sum [/i]from the [i][/i]list of objects on tab [img]https://wiki.geogebra.org/uploads/thumb/4/4e/Geogebra-logo-elipse.svg/16px-Geogebra-logo-elipse.svg.png[/img].[/td][/tr] [tr] [td]15.[/td] [td][img]https://wiki.geogebra.org/uploads/thumb/d/db/Stylingbar_icon_graphics.svg/32px-Stylingbar_icon_graphics.svg.png[/img][/td] [td]Match colors of corresponding angles and text. [/td][/tr][tr] [td]16.[/td] [td][icon]https://wiki.geogebra.org/uploads/thumb/3/30/Menu-options.svg/120px-Menu-options.svg.png[/icon][/td] [td]Fix the text that is not supposed to be moved.[/td][/tr][/table]