Drawing a Parabola

Introduction

• Parabola with base 100 mm and height 80 mm
• Two methods: Rectangular method and Tangent method

Initial Setup

1. Set unit and limit
2. Zoom the window
   • Type Z, press Enter
   • Type A, press Enter

Rectangular Method

Drawing the Rectangle

• Use the line command to create a rectangle
  • Specify first point
  • Draw horizontal line of 100 mm
  • Enable ortho mode to draw vertical line of 80 mm
  • Close the rectangle by typing C and pressing Enter

Dividing the Rectangle

• Divide the rectangle into two equal parts by joining midpoints of top and bottom edges
• Divide the baseline into 10 equal parts using the divide command
  • Select the line to divide
  • Specify 10 equal parts

Making Points Visible

• Type DT to change point styles
• Adjust point size if needed

Dividing the Vertical Line

• Divide the vertical line into 5 equal parts
• Ensure the vertical line is divided in the same number of parts as the baseline

Drawing Lines

• Draw horizontal lines from each base point to the top line
• Draw inclined lines from vertical points to the vertex point
  • Switch off ortho mode for inclined lines

Marking Intersection Points

• Use point command to mark all intersection points from inclined lines

Mirroring

• Use the mirror command to duplicate lines and points
  • Select objects to mirror
  • Specify mirror line points

Drawing the Parabola Curve

• Use the spline command to create the parabola curve
  • Start from the base point to each marked intersection point
  • Finalize the curve by moving the cursor outside and pressing Enter

Final Adjustments

• Differentiate construction lines from the parabola curve by changing thickness and color
  • Use line width command to enable width display
  • Optionally, color the parabola curve

Dimensioning

• Add dimensions for base (100 mm) and height (80 mm)

Tangent Method

Drawing the Triangle

• Draw a base line of 100 mm
• Create a triangle with height 160 mm (80 mm + 80 mm)

Dividing the Triangle

• Divide slanting lines of the triangle into 6 equal parts
  • Select the lines and use divide command

Joining Points

• Draw inclined lines between corresponding points on left and right slants
  • Pair points for joining (1-1, 2-2, etc.)

Drawing the Parabola

• Use the spline command to create the parabola within the triangle
  • Start from the base point and choose midpoints

Final Adjustments

• Differentiate the parabola by adjusting thickness and color
• Dimension the base and height (100 mm and 80 mm)

Conclusion

• Successfully drawn parabola using both methods.