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# Constructing a Regular Hexagon from Triangles

Best Answer Rainman, 16 November 2013 - 08:13 PM

Spoiler for ruler and compass

Go to the full post

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Posted 16 November 2013 - 03:31 AM

In the figure, triangles ABC, DEF, and GHJ are congruent isosceles triangles.  Angles B and C are 80 degrees.  Points AEFC, EHJD, DFB, and GHF are collinear.  Without drawing a circle, show how to mark the corners of a perfect hexagon on the diagram, using only a compass set to a constant length.  Prove it's a perfect hexagon.

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### #2 Rainman

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Posted 16 November 2013 - 08:13 PM   Best Answer

Spoiler for ruler and compass

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### #3 bonanova

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Posted 18 November 2013 - 09:16 AM

Cool. I didn't find the initial 120o angle.

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Vidi vici veni.

### #4 plainglazed

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Posted 18 November 2013 - 06:35 PM

Spoiler for similar to Rainman

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Posted 19 November 2013 - 05:42 AM

yeah, i took it for granted that we could draw a straight line...

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