1) Select the POINT [icon]/images/ggb/toolbar/mode_point.png[/icon] tool. Use this tool to plot 3 points anywhere on the gray plane. [br][br]2) Select the MOVE [icon]/images/ggb/toolbar/mode_move.png[/icon] arrow. Click twice on any one of the points you plotted in step (1). Use this tool to [br] move this point off of the gray plane. Repeat this process for the other 2 points. [br][br]3) Select the PLANE THROUGH 3 POINTS [icon]/images/ggb/toolbar/mode_planethreepoint.png[/icon] tool. With this tool highlighted, select the 3 points you [br] initially plotted in step (1). This will create a plane that passes through these 3 points. [br] [br][b][i]Further directions appear below this applet. [/i][/b]

4) Select the MOVE [icon]https://www.geogebra.org/images/ggb/toolbar/mode_move.png[/icon] arrow. Use this tool to drag any one (or more) of these 3 points around. Notice [br] how the plane you plotted in (3) always passes through these 3 points. [br][br]5) Now select the INTERSECT 2 SURFACES [icon]https://www.geogebra.org/images/ggb/toolbar/mode_intersectioncurve.png[/icon] tool. Select the plane you plotted in step (3). Then select [br] the gray plane. This will now plot the intersection of these 2 surfaces (here, planes). [br][br]6) Select the MOVE [icon]/images/ggb/toolbar/mode_move.png[/icon] tool again. Drag any 1 (or more) of the 3 points you plotted in the first step. [br] Then answer the question that follows.