Calculus: Volumes of Known Cross-Section - 3D Printed
Three-dimensional objects can be made by placing two-dimensional objects on top of another two-dimensional object.
In the picture below, squares with thickness are placed on top of a circle. The dimensions of the square are determined by the location of the square on top of the circle: the side length of the square is the same as the chord length of the circle.
The three-dimensional object on the left has nine squares, and the three-dimensional object on the right has about 1000 squares. As the number of squares increase, the thickness of the squares decrease.