Polygons can be sorted and classified using different attributes, such as number of sides.  [br][br]For example, all polygons with four sides are classified as quadrilaterals – [i]quadri [/i]meaning four, [i]laterals [/i]meaning sides.[br][br]In this activity, you will use two [i]GeoGebra [/i]tools to learn more about classifying polygons, the POLYGON tool [icon]/images/ggb/toolbar/mode_polygon.png[/icon]and the REGULAR POLYGON tool [icon]/images/ggb/toolbar/mode_regularpolygon.png[/icon]. [br][br][b]Step 1. Construct and Experiment with a Polygon[/b][br]Select the POLYGON tool [icon]/images/ggb/toolbar/mode_polygon.png[/icon].  [br]Starting at Point A, construct a quadrilateral, any quadrilateral.[br][br]Select the ANGLE tool [icon]/images/ggb/toolbar/mode_angle.png[/icon].  Click near the center of your quadrilateral.  This will measure and label all four of the angles in your quadrilateral.[br][br]Select the DISTANCE OR LENGTH [icon]/images/ggb/toolbar/mode_distance.png[/icon] tool.  Click on each side of your quadrilateral to measure and label the length of each side.[br][br]Use the MOVE tool [icon]/images/ggb/toolbar/mode_move.png[/icon]to grab and move corners of your quadrilateral.  Observe the changes in the measurements of the angles and the sides.[br][br][b]Step 2. Construct and Experiment with a Regular Polygon[/b][br]Select the REGULAR POLYGON tool [icon]/images/ggb/toolbar/mode_regularpolygon.png[/icon].  [br]Starting at Point B, click to begin constructing a [b][i]regular [/i][/b]quadrilateral. [br][br]After you click to create the second point, the tool will ask how many sides you want on your regular polygon.  Just leave it set for 4 sides – a quadrilateral.[br][br]Select the ANGLE [icon]/images/ggb/toolbar/mode_angle.png[/icon] tool.  Click near the center of your [b][i]regular [/i][/b]quadrilateral to measure and label all four of the angles in your regular quadrilateral.[br][br]Select the DISTANCE OR LENGTH tool [icon]/images/ggb/toolbar/mode_distance.png[/icon].  Click on each side of your regular quadrilateral to measure and label the length of each side.[br][br]Use the MOVE tool [icon]/images/ggb/toolbar/mode_move.png[/icon] to grab and move corners of your [b][i]regular [/i][/b]quadrilateral.  Observe the changes in the measurements of the angles and the sides.[br][br][b]Step 3. Draw Conclusions[/b][br]So, what seems to be the difference between a polygon and a regular polygon?  [br]What makes a regular polygon “regular?”