The portion of the end of the cylinder covered by the liquid is called a circular segment. The area of the circular segment covered by liquid in a cylinder of radius r is given by
area = r2(θ - Sin[θ])/2, where θ = 2ArcCos[(r-h)/r] and h is the height of the liquid in the cylinder.
Multiply the segment area times the length of the cylinder to get the volume of the liquid.
_____
The angle is in radians.
area = r2(θ - Sin[θ])/2, where θ = 2ArcCos[(r-h)/r] and h is the height of the liquid in the cylinder.
Multiply the segment area times the length of the cylinder to get the volume of the liquid.
_____
The angle is in radians.