Bevel question

[Rangeball]

If a broadhead is advertised as having a 20* bevel, does that mean that the total angle of the edge is 20*, or is each half of the edge 20*

I have a bench top upright belt sander with an angle adjustable metal work table, and I want to make sure I set the angle right.

And yes I'll work slow and cool the head often so as not to mess up the temper  

Thanks.

[VA Bowbender]

It means that each side is sharpened at 20 degrees.
Don't you have a whetstone? It would be better than a belt sander.

[Rangeball]

Thanks.

I just want to use the sander to set the bevel, then move on to more fine sharpening for the final edge.