Construction of a regular pentagon:
Let N,S,E,W be the points of a circle C with center O in the four compass directions, and let M be the midpoint of ON.
Let E' and E" be the points where the circle with center M through E meets the line NS.
Finally, let P' and P" be the points where the circle with center E through E' meets C and let Q' and Q" be the points where the circle withcenter E through E" meets C.
Then E, P', P", Q' and Q" form a regular pentagon.
vrijdag 20 juli 2001