Using Orthogonal Mode

Orthogonal Mode restricts the movement of the cursor to be parallel to the X-axis or the Y-axis of the current coordinate system. For example, with the default 0-degree orientation (angle 0 at the "three o'clock" or "east" position), when the Orthogonal Mode setting is enabled, lines are restricted to 0 degrees, 90 degrees, 180 degrees, or 270 degrees. As you draw lines, the rubber-banding line follows either the horizontal or vertical axis, depending on which axis is nearest to the cursor: type the length of the line in the command bar, then press Enter.

NOTES

When you enable the Isometric snap style, cursor movement is restricted to orthogonal equivalents within the current isometric plane.
You can rotate the Orthogonal Mode axes using the Snap Angle setting.
Press and hold the Shift key to reverse the Orthogonal Mode setting.
Orthogonal Mode is overruled by entity snaps.
Turning on Ortho Mode automatically disables Polar Tracking and vice versa.

To toggle Orthogonal Mode

Do one of the following:

Click the ORTHO field in the Status Bar.
Press the F8 function key.
Press and hold the Shift key.
Type ortho in the command bar, then choose the appropriate setting.
Set the Orthogonal Mode in the Settings dialog.