Appleton's cyclopædia of drawing, designed as a textbook for the mechanic, architect, engineer, and surveyor (1866)
Worthen, William Ezra, 1819-1897, [from old catalog] ed, Appleton, firm, publishers, New York. (1866. D. Appleton & co.) [from old catalog] · New York, D. Appleton and company · leaf 25
dat the centre of the circle, the angleis measured by the arc enclosed be-tween the sides. Thus the angleDOB is measured by the arc DB; theline DPI, a line drawn from one ex-tremity of the arc perpendicular tothe radius passing through the otherextremity is called the sine of theangle, GD is the… … ._A-
