Define cavaliers principle

Cavalieri's Principle states that if two solids have the same height and cross-sectional area at every level, they have the same volume. This principle can be applied regardless of the shape of the solids, as long as the aforementioned conditions are met. It is often used in geometry and calculus to determine volumes of irregular shapes by comparing them to known solids. Essentially, it highlights the importance of cross-sectional area in calculating volume.