Select the line.
Press R to get the Rotate tool.
Alt click the end point of the line.
Rotate while holding the Alt key to make a copy.
Press Cmd D or Ctrl D to repeat.
Or Alt Click with the rotat tool on the endpoint to get the rotate dialog.
Fill in the angle and click Copy.
Repeat with Cmd D or Ctrl D
Good to hear that worked.
As you have seen in this thread, there are many ways of doing this in Illustrator.
I would prefer the Transform Effect solution from SJRiegel, it is the most flexible because you can always change the number, length and angle of the lines.
What is the best method to trim the lines to my border??
I've tried the knife and eraser...
I would use the Shape Builder tool (Shift M)
Draw a rectangle with only a fill and send it to the back.
Select the lines and the rectangle.
Hold down the Alt key and drag with the Shape Builder over the parts you want to delete.
Delete the rectangle.
Thank you!! I knew there was a better way. I am just learning, and this is a wonderful group of helpers!!
Usually it is considered as some kind of curse, but if you are using the English version of Illustrator you could also take the Line tool, hold down the Tilde key and then click and freehand drag around to duplicate the lines en masse.
In other international Illustrator versions the modifier key may vary.
I'd use Transform Effect.
One line wtih Effect > Distort and Transform > Transform applied with whatever settings work for you.