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
Rebate plane Rebate plane The rebate plane (also known as the rabbet plane) is a hand plane designed for cutting rabbets in wood. It's a simple tool used in many Western countries with hundreds of years of history. It was in use in England at least as early as the 11th century. The rebate plane is one of a group of planes, including the shoulder plane, bullnose plane and carriage makers plane, in which the blade protrudes by a very small amount - usually less than half a millimetre - from the sides of the plane body on both sides. The blade