Page:Sheet Metal Drafting.djvu/222

208 lengths of the lines needed to develop the pattern. The section A to 2 has for its base line the true length line A to 1 of Fig. 296; therefore, both base and hypotenuse of this section are used in the development of the pattern. This is also true of section E to 7.

The pattern, Fig. 300, is started by drawing a vertical line

equal in length to line A-1 of Fig. 296. With point A as a center and a radius equal to the hypotenuse of section A to 2, an arc is drawn bearing away from point 1. This is intersected by an arc drawn from point 1 with a radius equal to line 1-2 of the true section. Fig. 296. This establishes point 2.