 | John Fry Heather - 1851 - 228 páginas
...line LM (pl. I., fig. 3) as the intersection of the two planes of projection, let the straight line? ab, a" b", be the given projections of a straight...may be found, when their projections on two planes arc known ; for an edge of such a body must either be parallel to one of the planes of projection,... | |
 | William S. BINNS - 1857 - 220 páginas
...lastly, projection from the lower to the upper plane. In all these examples it has been understood that the two planes of projection are at right angles to each other, the upper plane being vertical and the lower plane horizontal. It is now proposed to explain the projection... | |
 | William S. Binns - 1889 - 242 páginas
...lines. CHAPTER IV. PKOJKcri'iN FROM THE LOWER TO THE UPPF.K PLANE. ART. 51. — It has been shown that the two planes of projection are at right angles to each other (ART. 3). Consequently, if any given point, a, in Fig. 28 the horizontal plane be supposed to represent... | |
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... projections of a straight line whose length is required. Draw through a" an indefinite straight line H e meeting bb" at the point e, and from e measure a distance, e H, in the direction e a", equal to ab ; then H b", the hypotheneuse of the right... 