These are 2 of 6 sawhorses I made 20yrs ago from an article in a woodworking magazine.
Each one is made by starting with 10 30" 2x4's ripped to 3"wide.
They take up a lot of room for storage, but they're built like tanks.
They can be a little short, but they make a great work platform when working on large projects. Not only have they held heavy crates while being repaired, but they've also been used as staging platforms while painting tall walls.
I don't remember the angle that was used for the cuts (I use a template so I don't have to remember), but to make taller units you'd have to change the angles anyway.
The last picture shows the template I used to make the legs. The rungs were fit into the half-miters and glued and screwed in place.
IIRC, the original plan had a chain between the halves to keep them from spreading. I used 3 hinges and a few scraps of 1X3 instead.