Wiktionary
set squares
n. (set square English)
Usage examples of "set squares".
Near Juniper, Laurel Wilson, Alex Barstow and Nigel Loring bent over a table crowded with drawings, and weighted down with slide rules, compasses and set squares.
On the starboard side, but close to the middle, is a plain oak drawing-table with drawing-board, T-square, straightedges, set squares, mathematical instruments, saucers of water color, a tumbler of discolored water, Indian ink, pencils, and brushes on it.