So you can create a sphere in Sketchup
- In order to get later a ball shown, you have to draw first a circle. To do this, select the circle tool. The circle should have the size to later have the ball.
- Now click on the tool for Copy-Move. Press and hold the [Ctrl] key pressed while you select the circle and move up. By Holding the button, the circle will be copied automatically.
- In the next step, turn the circle with the "Rotate"tool in the Vertical.
- Next, you use the "follow me" tool from the extended feature set. This should be not displayed, find it under view > toolbars > toolbars Large tool set.
- You click on the selection tool and select the bottom, so your first circle. Then you need to select the "follow me"tool and click on the top, perpendicular circle. Is created into a ball, and you can delete the bottom circle now.

Google SketchUp: ball-create (Screenshot)
In SketchUp, objects are used to show and hide, we will show you in a further practical tip.