Hexagon circle) with vertices given by the six intersections of the edges of a triangle and the three lines that are parallel to the edges that pass through its symmedian point. If the successive sides of a cyclic hexagon are "a", "b", "c", "d", "e", "f", then the three main diagonals intersect in a single point if and only if . If, for each side of a cyclic hexagon, the adjacent sides are extended to their intersection, forming a triangle exterior to the given side, then the segments connecting the circumcenters of opposite triangles are concurrent. If a hexagon has vertices
A Plane Is Born training at Staverton Airport in Gloucestershire with instructor Carl Bowen. - Building Begins Mark learns that before he starts to build his aeroplane he must attend a workshop on composite building techniques. His crash course is instructed by expert Neville Eyre. In part 2, back at the workshop, he begins work on his kit plane, starting with the Rudder. Some respite from plastics is provided at Gloucester airport where his flying training continues apace. In a regular feature, Dudley Pattison shows us the Isaac's Fury biplane he took fifteen years to build. - Wings Filming in the workshop, work begins