and the reason you couldnt get it is that a set square doesnt draw angles - or at lease didnt in the sixties - and the correct answer is a "protractor"
A Protractor measures angles.....a set-square (fixed) is usually 30-60-90, or 45-90.....whereas an adjustable set-square can be altered to any desired angle.
It doeS draw angles 90 45 60 or 30 degees It's a form of t square with an additional arm turning on a pivot For drawing lines at fixed angles to the head
You can draw an angle with a protractor (any angle) or set squares as JTH mentioned (only 30, 45,60,90 or multiples). A T-square is what you place on a drawing board to ensure a horizontal/vertical edge to rest your set squares etc against.