I can't resist these when I come across them; they just make me want to sit down and make geometric drawings. I found these three together and have to think they have been together for a long time, together making an excellent set. The dark one was once marked as a ruler on the hypotenuse; now mostly faded, but a few inches remain visible. The scalene triangle is marked with a Sphynx logo, which I have not been able to place. I'd guess all three date to 1900 or so. Lovely.
9 3/4 hypothesis of largest. 8 3/4” hypothesis of dark All in very good condition, with a bit of darkening to the larger blonde one on one side.