The regular octagon is a polygon whose eight sides are equal and the eight vertices are equidistant.
- Draw two segments [AB] and [CD] perpendicular to their center O and equal to the width of the desired figure.
- Draw the sides of the square ACBD.
- Place the media on the 4 sides of the square.
- Draw two lines (FG) and (HI) passing through the midpoints of two opposite sides and the center O of the square.
- Place the points F, G, H and I so that OF = OG = OH = OI = OA.
- Connect the points F, G, H and I to the four vertices of the square ACBD to draw the octagon.