Trisecting the Angle

Classic Problem
Trisecting the angle is dividing a given angle into three equal parts..

Also see

 * Trisecting the Angle by Compass and Straightedge Construction is Impossible


 * Trisection of Angle by Archimedean Spiral
 * Trisection of Angle by Neusis Construction
 * Trisection of Angle by Parabola


 * Squaring the Circle
 * Doubling the Cube