Prueba
Open GeoGebra and be sure the Algebra & Graphics view is displayed (Perspectives menu).To create point A at the origin, type A = (0,0) in the Input bar and press the ENTER key on your keyboard.
2.) Next, to construct a circle with center A and radius 1, type circle[A,1] in the Input Bar and press the ENTER key on your keyboard.
3.) We fix point A to prevent it from being accidentally moved. To fix the position of point A, right click on point A, and then click Object Properties from the context menu. This will display the Preferences dialog box shown in Figure 2.
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