The combination of "Solid Geometry 1938" carefully hand-written and upper right and the resting of this student's foot against the edge of a desk across the aisle--knee and ankle forming two near perfect right angles-- completely does it for me, the gesture itself an embodiment of the phrase, and the image itself just perfectly composed. It is stamped on the back "H. Hagens-Knoop," a photographer I've found just a couple of records for: several photos in the archive of the New York Heritage Collection relating to the Tomkins Cove Union Free School in Tomkins Cove, New York. For me this one is both perfectly specific and rather transcendent.

4 5/16" x 3 3/16", good condition. Printed on heavy weight matte paper/light card.