Polygon Rotate around Point New! Point Segment Rename Angle Slider Move Preparations Open a new GeoGebra window. Switch to and show the coordinate axes. Perspectives Geometry – Click on Preferences in the Toolbar and choose Graphics to open the Properties dialog for the Graphics View. On tab xAxis change the Distance to 1. On tab yAxis change the Distance to 1. Introduction of new tool New! Rotate around Point Hint: Click the object to be rotated, the center of rotation and enter the angle in the appearing dialog window. Hints: to read the Toolbar help if you know how to use the tool. Don’t forget don’t Try out the new tool before you start the construction. Construction Steps Create an arbitrary triangle ABC in the second quadrant placing the 1 vertices on grid points. 2 Create a new point D at the origin of the coordinate system. 3 Rename the point D to O. Hint: Just type to open the Rename dialog. “O” 4 Create a slider for angle α. Hint: In the Slider dialog window check Angle and set the Increment to Make sure you delete the 90˚. don’t ˚ symbol. 5 Rotate triangle ABC around point O by angle α. Hint: Check counter clockwise rotation. 6 Create segments AO and A’O. 7 Create angle AOA’.
Polygon Rotate around Point New! Point Segment Rename Angle Slider Move Preparations Open a new GeoGebra window. Switch to Perspectives – Geometry and show the coordinate axes. Click on Preferences in the Toolbar and choose Graphics to open the Properties dialog for the Graphics View. On tab xAxis change the Distance to 1. On tab yAxis change the Distance to 1. Introduction of new tool Rotate around Point New! Hint: Click the object to be rotated, the center of rotation and enter the angle in the appearing dialog window. Hints: Don’t forget to read the Toolbar help if you don’t know how to use the tool. Try out the new tool before you start the construction. Construction Steps 1 Create an arbitrary triangle ABC in the second quadrant placing the vertices on grid points. 2 Create a new point D at the origin of the coordinate system. 3 Rename the point D to O. Hint: Just type “O” to open the Rename dialog. 4 Create a slider for angle α. Hint: In the Slider dialog window check Angle and set the Increment to 90˚. Make sure you don’t delete the ˚ symbol. 5 Rotate triangle ABC around point O by angle α. Hint: Check counter clockwise rotation. 6 Create segments AO and A’O. 7 Create angle AOA’.
ggb-intro-en44-2014-07-17.docx