Bisecting a line segment is the most basic and vital tool in constructions.
Given line AB, construct a circle with center A, and construct a circle with the same radius on point B. Connect the two intersections of the circles. They intersect line AB at it's bisector.
Given angle BAC, bisect angle BAC so that BAD=DAC.
First construct a circle centered at the vertex, A. Call the points where Circle A intersects angle BAC, P1 and P2. Measure the distance between P1 and P2, and draw a circle at P1 with radius P1P2. Do the same with P2. Call the intersection D. Connect D with A. DA is the bisector of angle BAC.
| Heptagon | Triangle and Hexagon | Pentagon | Golden Ratio | Nonagon |
| Pentadecagon | Heptadecagon | N-Gon | Squaring a Circle | More Constructions |
© 2002 Robin Hu