TRIG ONE
For every right triangle, you need the lenghth of two sides or one side and one angle ( not B angle:90) knowing this : leach devided by LP : co Sine angle A, leach squared - Lp = perp. which half or most the length of the luff call it X luff - X = remainder of luff call it Z Z squared + LP squared = length of foot, Z times LP devided by 2 = sq ft of bottom sect. AA leach times LP devided by 2 = sq ft of upper sect BB, aa+bb = total sail area.