Outstanding! I'm glad we could help. Thanks. 
Now on to your next question.
It depends. If the two lines intersect at 90 degrees to each other, you can use the "chamfer" tool in the "edit" tab. Remember, though, that a 1/4"(.25) chamfer will create a 1/2"(.5) long, 45-degree angled corner at the intersection. If the lines extend beyond the newly created corner, they will be "cut-off" and you may need to draw-in new lines if you still want them to continue beyond that corner.
If the lines are not at 90-degrees to each other, then you could use the "draw angled line" tool in the "line" tab. You may want to place a "temp point" on one of the lines as a "snap point" for one end of the angled line. You'll probably have to enter alternate degree values to create the "45-degree angle" in the desired orientation. The alternate values, from a straight vertical(0) or horizontal(180) line, are 45(of course), 135, 225 & 315.
If the line the 45-degree line is to be drawn from is not at 0 or 180 degrees, then you'll need to get the angle of the reference line using the "dimension" tab and add or subtract, in 45 degree increments, until you get the desired orientation.
Alternately, and I think an easier method would be to draw a temporary "perpendicular" line and use the "chamfer" tool, as previously described, to create a 45-degree angle between the two "odd angled" lines. This method would require no math or "guess work" either. I should think that it would also be more accurate.
As you can see, there are many "tricks" to accomplish the same results, depending on the situation.
Please note that if the result is not what you desire, you can always select the "undo" function in the drop-down "edit" menu at the top of the program window, up where the "file" menu is located, and try another value or method until you get the desired result.
You can use the "dimension" tab, "draw angle dimension between two lines" button to verify the angle between the two lines. The value should be one of the four alternatives listed above.
I hope this was helpful. (and not too lengthy or confusing)
Don't be afraid to experiment. You can always "undo" or "erase" any undesirable results and try something else.
You'll be a "pro" at it, soon.
Now on to your next question.
It depends. If the two lines intersect at 90 degrees to each other, you can use the "chamfer" tool in the "edit" tab. Remember, though, that a 1/4"(.25) chamfer will create a 1/2"(.5) long, 45-degree angled corner at the intersection. If the lines extend beyond the newly created corner, they will be "cut-off" and you may need to draw-in new lines if you still want them to continue beyond that corner.
If the lines are not at 90-degrees to each other, then you could use the "draw angled line" tool in the "line" tab. You may want to place a "temp point" on one of the lines as a "snap point" for one end of the angled line. You'll probably have to enter alternate degree values to create the "45-degree angle" in the desired orientation. The alternate values, from a straight vertical(0) or horizontal(180) line, are 45(of course), 135, 225 & 315.
If the line the 45-degree line is to be drawn from is not at 0 or 180 degrees, then you'll need to get the angle of the reference line using the "dimension" tab and add or subtract, in 45 degree increments, until you get the desired orientation.
Alternately, and I think an easier method would be to draw a temporary "perpendicular" line and use the "chamfer" tool, as previously described, to create a 45-degree angle between the two "odd angled" lines. This method would require no math or "guess work" either. I should think that it would also be more accurate.
As you can see, there are many "tricks" to accomplish the same results, depending on the situation.
Please note that if the result is not what you desire, you can always select the "undo" function in the drop-down "edit" menu at the top of the program window, up where the "file" menu is located, and try another value or method until you get the desired result.
You can use the "dimension" tab, "draw angle dimension between two lines" button to verify the angle between the two lines. The value should be one of the four alternatives listed above.
I hope this was helpful. (and not too lengthy or confusing)
Don't be afraid to experiment. You can always "undo" or "erase" any undesirable results and try something else.
You'll be a "pro" at it, soon.