Tangential quadrilateral all of whose sides are tangent to a single conic section has three diagonals that meet at a point. From a tangential quadrilateral, one can form a hexagon with two 180° angles, by placing two new vertices at two opposite points of tangency; all six of the sides of this hexagon lie on lines tangent to the inscribed circle, so its diagonals meet at a point. But two of these diagonals are the same as the diagonals of the tangential quadrilateral, and the third diagonal of the hexagon is the line through two opposite points of tangency. Repeating this same
A Plane Is Born the tail plane. In our regular look at the world of kit aircraft, we meet Steve Pike and Kevin Fagan who have just finished an Australian aircraft - The Jabiru. Back at Staverton Airport, it's a milestone in Mark's Flying progress - with his first solo flight. - Like my Wheels? Mark is back on familiar ground as he fits brakes, wheels and undercarriage to his aeroplane, Martin Dovey introduces us to his vintage Kit-Plane, the Kit Fox, and it is the turn of Navigation to further perplex Mark as he continues his flying lessons. - No Longer Topless A