The American house-carpenter; a treatise on the art of building, and the strength of materials (1867)
Hatfield, R. G. (Robert Griffith), 1815-1879 · New York, J. Wiley · leaf 33
Fig. 34. 77.— To bisect an angle. Let a b c, {Fig. 34,) be the angle to be bisected. Upon b, with any radius, describe the arc, a c ; upon a and c, with a radius greater than half a c, describe arcs cutting each other at d ; join b and d ; and b d will bisect the angle, a b c, us was required. This… … Fig. 35. 78.— To trisect a right angle. Upon a, {Fig. 35,) with any radius, describe the arc, b c ; upon b and c, with the same radius, describe arcs cutting the arc, b c^aX d and e ; from d and e, draw lines to a, and they will trisect the angle as was required. The truth of this is made evident…
Carpentry · Architecture
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