Spanton, J. Humphrey (John Humphrey) · London, Macmillan and Co., Limited; New York, The Macmillan Company · leaf 107
d AD,which will form the scaleof chords. . ??- To use this scale insetting off an angle—forexample, to draw a linethat will make an angleof 40° with line CB (Fig.192). With C as centre, andradius equal to A60 onthe scale of chords, draw an arc BFD. With a pair of dividers,take the distance A40 from… … 134. To construct any angle without a protractor. Draw CD perpendicular to AB. With C as centre, andCA as radius, draw the semicircle ADB. Trisect the angleDCB in E and F (Prob. 13). Trisect the angle ECB in H andK (Prob. 14). Bisect FKin L (Prob. 12). ThenDE = 3o°,EH = 2o°,HF=io°,and FL = 5°.…
Geometrical drawing · Design · Drawing
Internet Archive · Wellesley College Library · Public Domain Mark 1.0. Free to use for anything.
