Use Rotate 45 
to rotate the selected part of the picture by 45 degrees.
Note: When an area is chosen with one of the selection tools, only the area that was selected is rotated, even if the selection box appears rectangular.
Rotate 45 
is dimmed if there is no selection.
To use Rotate 45
-
In the Paint Tab
of the Design Panel 
, click Rotate 45 
. -
Choose Paint > Rotate 45.