The sheet-metal worker's guide : a practical handbook for tinsmiths, coppersmiths, zincworkers, etc., comprising numerous geometrical diagrams and working patterns, with descriptive text (1888)
Crane, W. J. E. (W. J. Eden) · London : Lockwood and Son · leaf 52
40 THE SHEET-METAL WORKER's GUIDE. is a parallelogram having only the two oppo- site sides equal and also the opposite angles equal. The trapezoid (centre figure, Fig. 31), which has two parallel sides only, but may have some … Fig. 31. of the sides or some of the angles equal to each other or not. The trapezium (right-hand figure, Fig. 31), which has none of its sides parallel, but some of the sides and some of the angles may or may not be equal to each other, or all the sides and the angles may be unequal. A trapezium,…
Sheet-metal work
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