In workshop practice it is a good plan to have a protractor or bevel with which to set out angles. A useful protractor can readily be made out of sheet brass or aluminium, as in Fig. 84. The semicircle being about a foot in diameter. The protractor, as shown, is divided into 10° divisions; but if it be made 12 in. in diameter there should be no difficulty in subdividing into divisions of 1°. The distance apart of the division lines on the circumference would in this case for 1° be about 1-10 in. apart.