Menu: View->Rotate
Mouse menu: Rotate
Toolbar: 
There are various ways to rotate the image in order to view it from different angles. This does not affect the geometry.
Note: Instead of picking twice to begin and end the rotation, hold down the left mouse button and move the cursor. View Menu>Rotate>Trackball
With this option you can rotate the image as if using a trackball device. This means that when you left-click on a point and move the mouse, the geometric point tries to follow the mouse pointer. This can be imagined as a ball over the graphical window which is moved with the mouse.
The left mouse button can be pressed several times to engage and disengage the movement. To cancel this function, use escape (see Escape).
View Menu>Rotate>Screen axes
This option allows a dynamic rotation about the screen axes. Screen axes are defined as:
- X-axis: The horizontal axis.
- Y-axis: The vertical axis.
- Z-axis: The axis at a right angle to the screen.
...