Cavalieri's principle is used...

to compare the volumes of solids

29

to find pime numbers less than 2971

24

to find all prime numbers from interwal

57

to check if given number is prime or not

41

In geometry, Cavalieri's principle, a modern implementation of the method of indivisibles, named after Bonaventura Cavalieri, is in 3-dimensional case: Suppose two regions in three-space (solids) are included between two parallel planes. If every plane parallel to these two planes intersects both regions in cross-sections of equal area, then the two regions have equal volumes.