You can use the Measure tool to rotate a view to make a specified edge in it horizontal. The clearest way to determine the desired rotation angle is to create two construction lines: one parallel to the edge, and one horizontal. The required angle is then easier to see.
To rotate a view,
1. Click Annotation and then, in the Setup group, click the arrow next to Properties.
2. Click View.
3. Select the view to rotate in the viewport. The View Properties dialog box opens.
4. Specify the rotation angle in Angle on the General tab.
The current angle of the view is displayed in the Angle box, highlighted in yellow. Note that the rotation angle is absolute. Therefore, if the angle is not zero you need to reset it to zero: Enter zero in the Angle box. Now repeat the first four steps above.
5. Click Annotation, Geometry, or Insert and then, in the Utilities group, click the arrow next to .
6. Click Angle. The Measure dialog box opens.
7. Click the two construction lines in the correct order to define the rotation angle between the edge and the horizontal axis. Graphical feedback indicates the angle being defined.
Measure measures angles counterclockwise. A different angle results depending on the direction you click the points.
The specified angle appears in the Angle Output field of the Measure dialog box.
8. Click in the Measure dialog box.
The measured angle now appears in the Rotate View menu.
9. Click in the Rotate View menu.
The view rotates so that the specified edge is horizontal.