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Accurately construct a heptagon with our simple guide
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A regular heptagon (also called septagon) is a polygon with seven equal sides and seven equal angles.[1] Accurately constructing polygons is an important part of geometry, and for regular heptagons there are multiple ways to draw one. Here is the easiest method if you are using a straight edge and compass.

  1. 1
    Draw an arbitrary circle, centred at a point . Keep in mind that you will need some extra space around the circle for construction lines.[2]
  2. 2
    Draw the radius .[3]
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  3. 3
    Draw a circle with radius , centred at . This circle intersects the first circle at points and .[4]
  4. 4
    Connect and . bisects in .[5]
  5. 5
    Draw a third circle with radius , centred at . This circle intersects circle a in .[6]
  6. 6
    Use your compass to trace the distance BD around the circle. You should end up exactly where you started. There is an error of about .2% for this method, which is negligible for any heptagon that fits on a regular A4 piece of paper. If you don't end up exactly where you started, there were probably some inaccuracies with the construction tools (e.g. the thickness of the pencil).[7]
  7. 7
    Connect adjacent vertices.
  8. 8
    Erase the construction lines if needed.
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Warnings

  • Since 7 cannot be written as the product of a power of two and a Fermat prime, it is impossible to do an exact compass and straightedge construction of a heptagon.[8] However, the above method has an error of less than 0.2%. When the circumscribed circle of the heptagon has a radius of 1 meter, there will be an error of approx. 1.7 mm.
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Things You'll Need

  • Paper
  • Compass
  • Straight edge
  • Pencil
  • Pen
  • Eraser

About This Article

wikiHow is a “wiki,” similar to Wikipedia, which means that many of our articles are co-written by multiple authors. To create this article, 9 people, some anonymous, worked to edit and improve it over time. This article has been viewed 134,216 times.
226 votes - 68%
Co-authors: 9
Updated: February 13, 2026
Views: 134,216
Categories: Compass Constructions
Thanks to all authors for creating a page that has been read 134,216 times.

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