Parabolic Envelope from Congruent Triangles

Consider a line and a point not on . Drag the orange point along . Draw a vertical line from . The perpendicular bisector of meets at a point that traces out a parabola and is tangent to the parabola. The focus and directrix of the parabola are and because is isoceles. The part of the vertical line m inside the parabola is the reflection in of the ray .



  • [Snapshot]
  • [Snapshot]
  • [Snapshot]


    • Share:

Embed Interactive Demonstration New!

Just copy and paste this snippet of JavaScript code into your website or blog to put the live Demonstration on your site. More details »

Files require Wolfram CDF Player or Mathematica.

Related Curriculum Standards

US Common Core State Standards, Mathematics