tailieunhanh - autocad 2007 and autocad lt 2007 bible - phần 3

Tại các đối tượng Select để mở rộng hoặc thay đổi lựa chọn để cắt hoặc [Hàng rào / Crossing / Dự án / Edge / Undo]: nhắc nhở, chọn dòng 2 trong Hình 1-20. Nhấn Enter để kết thúc các đối tượng lựa chọn. Lệnh này mở rộng dòng. 5. Lặp lại lệnh HẠN. Tại các đối tượng Chọn hoặc: nhắc nhở, chọn dòng 3 và 4 trong hình 10-20 và sau đó nhấn Enter. 6. | 218 Part II Drawing in Two Dimensions STEPS Extending Objects 1. Open from the CD-ROM. 2. Save the file as in your AutoCAD Bible folder. It looks like Figure 10-20. 3. Choose Extend on the Modify toolbar. At the Select objects or select all prompt pick the line at 1 in Figure 10-20 and then press Enter. Figure 10-20 An electrical schematic. 4. At the Select object to extend or shift-select to trim or Fence Crossing Project Edge Undo prompt pick the line at 2 in Figure 10-20. Press Enter to finish selecting objects. The command extends the line. 5. Repeat the EXTEND command. At the Select objects or select all prompt pick the lines at 3 and 4 in Figure 10-20 and then press Enter. 6. At the Select object to extend or shift-select to trim or Fence Crossing Project Edge Undo prompt right-click and choose Edge. Right-click and choose Extend at the Extend No extend No extend prompt. 7. Pick lines 3 and 0 in Figure 10-20 again at the points shown. The lines extend to meet. Press Enter to end the command. 8. Save your drawing. It should look like Figure 10-21. Figure 10-21 The completed electrical schematic. Chapter 10 Editing Your Drawing with Advanced Tools 219 Lengthening objects The LENGTHEN command both lengthens and shortens. It works on open objects such as lines arcs and polylines and also increases or decreases the included angle of arcs. You can change the length of an arc as well as its included angle by using LENGTHEN. AutoCAD and AutoCAD LT offer several ways of defining the new length or included angle. Use LENGTHEN if you want to lengthen or shorten an object when there is no available intersecting edge or boundary to use with TRIM or EXTEND. In the LENGTHEN command the length of an arc is measured along its circumference. Don t confuse this with the Length of Chord option of the ARC command which refers to the length of a line stretched from one endpoint of the arc to the other endpoint. ZTo lengthen or shorten an object choose Modify