I am a novice trying to build a ramp..  I need to drop a board 10" in 10'..  At what angle to I cut the ends of the board..

The next on is 11" in 11'.. what is that angle..

Hey Pat, welcome to our community.

I have done a few wheel chair ramps in a theme park I used to work at in the carpenter maintenance shop. At first we were cutting the angles for where the ramps would meet the sidewalk or concrete, and we basically did a test cut and test fit, cutting a little at a time then following up with porta planner till the proper angle was met. We stopped building the ramps this way and instead went with a ramp transition piece, it was much easier and quicker to build, and much more durable. The old way we did it the edges where the ramp met the sidewalk, would eventually crumble.

So here is what I would suggest, it'll make your life easier building the ramp, and it is more durable, there are several on the market these days.

 

https://www.homedepot.com/p/EZ-ACCESS-TRANSITIONS-Aluminum-Threshold-Ramp-6-5-in-L-x-34-in-W-x-1-in-H-TMER-1/203265849

 

Just set this over your ramp lip at the bottom of the ramp where it meets the walkway, no need to cut an angle in the wood, keep it squared off and set the ramp plate over the bottom edge of the ramp. You could even make one yourself with a little creativity. Just a straight flat piece of durable metal will do.

 

For the transition at the top of the ramp where it meets the landing, that can be filled in easily enough, or not at all depending on the gap.

Buying that threshold would certainly be the easiest, but I used a online calculator and using the info you show It looks like the end on the ground will be about 5° (4.76, to be exact) and the high end will be 85° (or 85.24 for the precision number). both the 10' and the 11' came out this way. I used this calculator, though there are a lot of them available. I didn't check these results, you might want to draw then on the plank and see if they look good

I've done a couple ramps also and used a variation of the cut and test method.  After getting the ramp stringers in place, set the bottom or top piece in place.  Using a level, square, 2x4 or anything straight - lay that on the ground against that piece needing the cut and mark the edge.  In a perfect world the top and bottom pieces will have the same cut - as Fred's calculator has shown.

 

And welcome aboard Patpurple, glad to have you here.  Please post up some progress pics...

 

 

 

 

 

 

 

 

drop 10 inches in 10 feet (120 inches)...so 1 inch per 12 inches.  so 1/12 = 0.083333.  the arctan of 0.08333=4.76 deg.  complimentary angle would be 90-4.76 =85.24 degrees.