Did you find the "rotate" icon in your tools? horizontal shaded bar, vertical black bar, circular arrow? When you click that, by default the rotation angle is set to 90 degrees, but a field
"Angle" appears in the top menu bar and you can change the angle to an arbitrary number.
You can also use a typed command in the command window, like "rotate R10" (rotate 10 degrees) or "rotate =R10" (rotate to 10 degree absolute angle.) Typed commands can be very useful for more exacting actions...