- Coordinates for 3D CAD Modeling
- Geometric Entities
- 4.1 Manually Bisecting a Line or Circular Arc
- 4.2 Drawing Tangents to Two Circles
- 4.3 Drawing an Arc Tangent to a Line or Arc and Through a Point
- 4.4 Bisecting an Angle
- 4.5 Drawing a Line through a Point and Parallel to a Line
- 4.6 Drawing a Triangle with Sides Given
- 4.7 Drawing a Right Triangle with Hypotenuse and One Side Given
- 4.8 Laying Out an Angle
- 4.9 Drawing an Equilateral Triangle
- 4.10 Polygons
- 4.11 Drawing a Regular Pentagon
- 4.12 Drawing a Hexagon
- 4.13 Ellipses
- 4.14 Spline Curves
- 4.15 Geometric Relationships
- 4.16 Solid Primitives
- 4.17 Recognizing Symmetry
- 4.18 Extruded Forms
- 4.19 Revolved Forms
- 4.20 Irregular Surfaces
- 4.21 User Coordinate Systems
- 4.22 Transformations
- Key Words
- Chapter Summary
- Skills Summary
- Review Questions
- Chapter Exercises

## 4.5 Drawing a Line through a Point and Parallel to a Line

With given point *P* as center, and any convenient radius *R*, draw arc *CD* to intersect the given line *AB* at *E* (Figure 4.27). With *E* as center and the same radius, strike arc *R*′ to intersect the given line at *G.* With *PG* as radius and *E* as center, strike arc *r* to locate point *H.* The line *PH* is the required parallel line.

**4.27** Drawing a Line through a Point

Using AutoCAD, you can quickly draw a new line parallel to a given line and through a given point using the **Offset** command with the **Through** option. Another method is to use the **Parallel** object snap while drawing the line as shown in Figure 4.28. You can also copy the original line and place the copy through the point.

**4.28** Drawing a Line through a Point