It's come to our attention that my 6th grader with dysgraphia is struggling with a particular chapter in math dealing with estimating degrees of an angle, finding lines of symmetry, etc.

For any of you who have dealt with this, any tips/tricks for a workaround or helping him get to the place he CAN see them?

Do you have any manipulatives your child could use to build 2-d or 3-d figures so that he would have an object to contemplate rather than a drawing?

There are kits like Zome that are specifically for math, but other building systems might also help -- KNex, maybe, or even Tinker Toys.

There's also a computer program called Geometer's Sketchpad that allows the user to create and rotate shapes; I don't know whether there are any similar programs online that are free, but it might be worth googling.

I think this is an indication that your 6th grader with dysgraphia also has problems with visual processing. Finding out exactly what is going on with the visual system might be more of a help, so that you could really design target interventions, or at least get accomodation so that estimating visual angles isn't required. This is purely a visual skill. That said, getting one of these and spending some time playing with it might help with the "estimating angles" problems. We found a set of these shape blocks pretty useful for developing a feel for different common angles and also for playing with the idea of symmetry. Getting a plain piece of mirror tile so the edge of the mirror can sit flush against the page and playing with that to see how reflection through a line works in practice might be helpful, too.