To trisect , place its leg on the x axis such that the vertex is in the coordinate system's origin. The coordinate system also contains the parabola . The unit circle with radius 1 around the origin intersects the angle's other leg , and from this point of intersection draw the perpendicular onto the y axis. The parallel to y axis through the midpoint of that perpendicular and the tangent on the unit circle in intersect in . The circle around with radius intersects the parabola at . The perpendicular from onto the x axis intersects the unit circle at , and is exactly one third of .
To trisect  place its leg on the x axis such that the vertex is in the coordinate system's origin. The coordinate system also contains the parabola . The unit circle with radius 1 around the origin intersects the angle's other leg , and from this point of intersection draw the perpendicular onto the y axis. The parallel to y axis through the midpoint of that perpendicular and the tangent on the unit circle in intersect in  The circle around with radius intersects the parabola at  The perpendicular from onto the x axis intersects the unit circle at , and is exactly one third of .