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- Objectives
- Objectives
- Overview
- Overview
- Coordinates for 3D Cad Modeling
- Coordinates for 3D Cad Modeling
- Geometric Entities
- Geometric Entities
- 4.1 Manually Bisecting a Line or Circular Arc
- 4.1 Manually Bisecting a Line or Circular Arc
- 4.2 Drawing Tangents to Two Circles
- 4.2 Drawing Tangents to Two Circles
- 4.3 Drawing an Arc Tangent to a Line or Arc and through a Point
- 4.3 Drawing an Arc Tangent to a Line or Arc and through a Point
- 4.4 Bisecting an Angle
- 4.4 Bisecting an Angle
- 4.5 Drawing a Line through a Point and Parallel to a Line
- 4.5 Drawing a Line through a Point and Parallel to a Line
- 4.6 Drawing a Triangle with Sides Given
- 4.6 Drawing a Triangle with Sides Given
- 4.7 Drawing a Right Triangle with Hypotenuse and One Side Given
- 4.7 Drawing a Right Triangle with Hypotenuse and One Side Given
- 4.8 Laying Out an Angle
- 4.8 Laying Out an Angle
- 4.9 Drawing an Equilateral Triangle
- 4.9 Drawing an Equilateral Triangle
- 4.10 Polygons
- 4.10 Polygons
- 4.11 Drawing a Regular Pentagon
- 4.11 Drawing a Regular Pentagon
- 4.12 Drawing a Hexagon
- 4.12 Drawing a Hexagon
- 4.13 Ellipses
- 4.13 Ellipses
- 4.14 Spline Curves
- 4.14 Spline Curves
- 4.15 Geometric Relationships
- 4.15 Geometric Relationships
- 4.16 Solid Primitives
- 4.16 Solid Primitives
- 4.17 Recognizing Symmetry
- 4.17 Recognizing Symmetry
- 4.18 Extruded Forms
- 4.18 Extruded Forms
- 4.19 Revolved Forms
- 4.19 Revolved Forms
- 4.20 Irregular Surfaces
- 4.20 Irregular Surfaces
- 4.21 User Coordinate Systems
- 4.21 User Coordinate Systems
- 4.22 Transformations
- 4.22 Transformations
- Key Words
- Key Words
- Chapter Summary
- Chapter Summary
- Skills Summary
- Skills Summary
- Review Questions
- Review Questions
- Chapter Exercises
- Chapter Exercises
This chapter is from the book
This chapter is from the book
This chapter is from the book
This chapter is from the book
4.11 Drawing a Regular Pentagon
Dividers Method: Divide the circumference of the circumscribed circle into five equal parts with the dividers, and join the points with straight lines (Figure 4.35a).
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4.35 Drawing a Pentagon
Geometric Method:
Step 1. Bisect radius OD at C (Figure 4.35b).
Step 2. Use C as the center and CA as the radius to lightly draw arc AE. With A as center and AE as radius, draw arc EB (Figure 4.35c).
Step 3. Draw line AB, then measure off distances AB around the circumference of the circle. Draw the sides of the pentagon through these points (Figure 4.35d).
