To rotate patches, first select them with the Select Tool and drag the white rotate handle on the middle top of them. Holding down the shift key will constrain the rotation to 15° increments. To rotate patches by 90°, just choose Edit > Rotate 90° CCW (Q) or Edit > Rotate 90° CW (W), or click the or button on the toolbar.
In many cases, you may want to rotate a patch to make an edge or the line between two vertices match the axis. To do so, drag the rotate center to one vertex. After you release the mouse button, the rotate handle will follow the cursor as it moves to let you locate another vertex. After that, rotate the patch by dragging. The line between the rotate center and the rotate handle will snap to axis automatically.Move Patches Split and Joint Patches