Descriptive geometry . section with a perpendicular to VN from c(Art. 42, page 30). Produce cV to VN, thusdetermining the line c5, and, therefore, Va^ is parallel to YN, a^ may be foundby drawing a parallel to VJV from b^ to meetthe perpendicular from a (Art. 35, page22). Likewise d is determined, since ed isparallel to VN. Next continue ed to theaxis at 7^; draw nd to meet od produced ate. The horizontal projection of the pentagonis best determined by Art. 35, page Fig. 82. 34 DESCRIPTIVE GEOMETRY 48. Construction 3. Fig. 83. Let it beassumed that tlie plane iV has been revolved
Descriptive geometry . section with a perpendicular to VN from c(Art. 42, page 30). Produce cV to VN, thusdetermining the line c5, and, therefore, Va^ is parallel to YN, a^ may be foundby drawing a parallel to VJV from b^ to meetthe perpendicular from a (Art. 35, page22). Likewise d is determined, since ed isparallel to VN. Next continue ed to theaxis at 7^; draw nd to meet od produced ate. The horizontal projection of the pentagonis best determined by Art. 35, page Fig. 82. 34 DESCRIPTIVE GEOMETRY 48. Construction 3. Fig. 83. Let it beassumed that tlie plane iV has been revolvedinto V about FTV as an axis, and that therevolved position of UN has been determined,as mSf, by revolving any point g of the hori-zontal trace of the plane about VJSf as an axis(Art. 43, page 31). The angle between RN^and VJV is the true size of the angle betweenthe traces of the plane; also the area betweenRN and FiV is the true size of that portionof plane JV lying between its traces. Next letit be assumed that the polygon has beendrawn in its revolved position, and occupyingits correct location with respect to FiV andffiV, e and d^ being two of its vertices. Tocounter-revolve, continue ed to intersect RNin k, and VN in ri. Since A; is a point in thehorizontal trace of the plane, its vertical pro-jection will lie in GrL. Then P will lie inCrL at the intersection of a perpendicular toFiV from k, and k^ is in RK Also the inter-section of ed with the axis VW is n^\ and its
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