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 82
own, therefore the angles a o d and ado are equal, and con-sequently the lines a o and a d are equal. {Art. 142.) 160.—Projposition. An angle at the circumference of acircle is measured by half the arc that subtends it: that is,the angle ah c^ {Fig. Ill,) is equal to half the angle a d c.Through… … Fig. 111. {Art 142,) and the sum of these two angles is equal to theangle a d e^ {Art 149,) and therefore one of them, ah d^ isequal to the half oi a d e. The angles a d e and a h d {ora he) are both subtended by the arc a e. Now, since the angle,a d e,ie. measured by the arc a e, which subtends…
Carpentry · Architecture
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