Angle Trisection Approximation

[AlphaBeta]

Hello!

Trisecting an angle using compass and straightedge (well... almost anyways).
http://www.youtube.com/watch?v=fkgGDw8Kt-M

Care to review?

Thanks!

[graynomad]

That's pretty clever, but I know a better way.

Use compass to find straight edge, then use straight edge to hoke out calculator from behind the sofa where it fell the other day.

Then use the calculator

Woops, there's a bug in that algorithm, compass has been defined as type "direction_finding_device", it should be "circle_drawing_device".

______
Rob

[liuzengqiang]

Nice work, very laborious. I'm drawing a blank in my head for angle/3. I haven't done hand drawings for ages. What software were you using?

[AlphaBeta]

Thank you!

I used GeoGebra. It's really awesome for construction

Code: [Select]

float trisect(float angle)
{
  static const int COMPASS_AND_STRAIGHTEDGE = 3;
  return angle / COMPASS_AND_STRAIGHTEDGE; //trisect using only compass and a straightedge
}

[amacmullen14]

In math class, we learned how to trisect an angle exactly (theoretically) on a piece of paper.  Requires folding the paper to make certain crease lines.