Scissor Question

[Rhino]

Over the holidays, I have been practicing scissor sharpening.  I sharpened two pairs.  One was a $5 dollar scissor - elementary school supply quality.  The other was a $40 sewing scissors. 
I note that in both cases, one blade of the scissor has a 60 degree angle and the other blade of the same scissor has a much higher angle, like 70 or more degrees. The thickness of the steel was too thin so I could not measure the angle accurately.

Is there some theory I should know about scissors?  Can I sharpen both blades to the same angle (60 degree for example) to save time and effort?  What is the benefit of having one blade at 60 degree and one blade at 70 degrees?  I understand, of course, the major risk is my wife would get upset.  Am I damaging the scissors by sharpening them both blades of one scissor at the same angle?

Thanks

[Herman Trivilino]

I've seen scissors with blades that are not symmetrical, for example, one might be serrated and the other not.  I've also noticed that in some scissors the bevel angle changes along the length of the blade. 

If you can't measure the bevel angle very well, how do you know the angles differ by 10 degrees?

If I'm in doubt, and the scissors are expensive and have an owner who's particular, I won't sharpen them.  On the other hand, if they're dull and I don't want to pay someone else to sharpen them, I'll do it myself.

[Rhino]

Thank you for the advice.  I will do that.

Just to clear things up, I should have said at least 10 degrees or about 10 degrees. It looked very different even though I could not measure it.  I also knew the angle was substantially different when I inspected the blade after some grinding but before the new angle was completely established.