[size=150]1) Use the POLYGON [icon]/images/ggb/toolbar/mode_polygon.png[/icon] tool to construct triangle [i]ABC[/i].  [br]2) Select the ANGLE [icon]/images/ggb/toolbar/mode_angle.png[/icon] tool.  Then click anywhere inside the polygon *** this will measure your angles automatically.[br] [br]3) Go to the Algebra view (click calculator icon upper left). [br][br]4) Calculate the sum of the measures of the interior angles of this triangle. Using Geogebra or Desmos calculator.[br]     (Start at 0:38 in video at the bottom if you're unsure of how to do this in GeoGebra). [br][br]Keep going!  There's a question below the app here. [/size]
    
        
     
    
    
            
            
[size=150]Select the MOVE [icon]/images/ggb/toolbar/mode_move.png[/icon] tool.  Move any one (or more) of the triangle's vertices around.  [br]What can we conclude about the [b]sum of the measures of the interior angles of this triangle[/b]?  [i]Be specific in your response! REMEMBER the RAP strategy.  "The sum of the measures of the interior angles of the triangle ..."[/i][/size]