Dip-Stick Problem
This was a difficult problem to solve

 Of course you have to assume the tank is level. This is d1.nb1 a1 Enter Diameter of Tank => 4 feet a2 Enter # of Gallons it holds => 3000 Gallons a3 Enter # of inches on the Dip-Stick => 22 inches This is d3.nb1 01 r = (a1/2) => Diameter to Radius 02 x = a3/12 => inches to feet 03 b1 = a2/7.48 => Gallons to Cubic Feet 04 b2 = Math.pow(r,2) => r Squared = r*r 05 b3 = 3.14159 => Pi = 3.14159 06 b4 = b2*b3 => Solving for length of tank 07 b5 = b1/b4 => Lenth of Tank in Feet 08 b6 = (r/1 - x/1) => one side of triangle 09 b7 = r*r/1 - b6*b6 => Pythagorean Theorem 10 b8 = Math.pow(b7,.5) => Other side of triangle 11 b9 = b8/b6 => Tangent of the angle 12 b10 = Math.atan(b9) => Calculate angle b10 = Math.atan(b9); 13 b11 = 2*b10 => Calculate circle angle 14 b12 = Math.sin(b11) => Get sin of the angle 15 b13 = (b11/1 - b12/1)/2 => part of formula 16 b14 = b13*r*r; 17 b15 = b5*b14 => Part of formula 18 b16 = b15*7.48 => Convert to Gallons 19 c3 = Reference # => input inches minus middle point 20 b17 = a2/2 - b16/1 => middle point minus input inches 21 b18 = a2/2 + b17/1 => Total Gallons => middle point plus difference 22 23 24 Let A = Angle Let R = Radius Formula: Area = (((A - Sin(A))/2)*R*R