Figure 4 : Sketch ellipse by ruler
Output of MD2002 06 16
Read Instructions
Keywords : Conic section - Ellipse
Highlight
  • Using ruler and tractor how to sketch ellipse ?
  • PF + PG = 2*a where a is major semi-axis.
  • Locus of P is an ellipse.
  • Equation of locus is x^2/a^2 + y^2/b^2 = 1.
  • F and G are fixed points which are called foci.
  • If light source is at F, then it will reflect from P to G.
Q1. How to sketch ?
A1. Answer : See daiagram
  • Sketch two fixed points F and G.
  • Sketch a line FQ = 2*a.
  • Join Q and G.
  • Bisect QG and the bisector meets FQ at P.
  • Then P is point on the locus. Since PF + PG = 2*a.
Reference
Show Room of MD2002 Contact Dr. Shih Math Examples Room
Copyright © Dr. K. G. Shih. Nova Scotia, Canada.
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