if a piece of flat card say 2" x 12" is placed on edge on a flat surface and curved so it's extreme limits touch two points say 11" apart, then tilt the card a few degrees, either the ends lift from the base or, the center lifts from the base. To shape a piece of card so it sits flat along the base yet is tilted inwards or outwards a given number of degrees requires a rectangle having three straight edges and the other edge curved. Can anyone show me a mathematical method of developing such a shape? One use of such a formulae is to construct the sides of a small boat which has an eliptical plan top and bottom, a flat bottom and sheered sides. (Although the sheered sides would need a shape having top and bottom edges curved) Help will be much appreciated.