In [url=https://www.geogebra.org/classic]GeoGebra Classic[/url], it is SUPER EASY for you and your Ss to explore cross sections and create surfaces of revolutions formed by rotating any cross section about an axis. [br][br]In the GeoGebra Classic app shown below, we simply[br][br]1) Dragged a picture (from the computer to the GeoGebra graphics pane) (0:00 - 0:05 in video)[br]2) Sketched a cross section the Freehand Shape tool [icon]/images/ggb/toolbar/mode_freehandshape.png[/icon]. (0:53 - 1:13)[br]3) Rotated this cross section about the [color=#ff0000]xAxis. [/color](1:56 - 2:05)[br][br]4) Rotated this image about the [color=#0000ff]zAxis[/color] to create a surface of revolution about the [color=#0000ff]zAxis[/color]. (2:16 - END)

1) Open up GeoGebra 3D Calculator on your device. [br][br]2) Go to MENU (upper left corner). Select OPEN. [br] Under SEARCH, type [b]adb4bfbp[/b][br] (Note this string of characters is in this GeoGebra resource URL). [br][br]3) Select the only 1 option that appears. [br][br]4) Move the bowl anywhere on the screen where you'd like. Press the AR button lower right.