Question

why is pluto not a planet​

Answer 1

Pluto is not a planet because it does not follow the all three criteria made by International Astronomical Union (IAU)

It meets all criteria except one that is it is not clear about his neighbouring regions of other planets

also some people say that pluto has irregular motion around sun but this is false pluto has it's own specific orbit which cut the orbit of other neighbouring planets.

Answer 2

Explanation:

The International Astronomical Union (IAU) downgraded the status of Pluto to that of a dwarf planet because it did not meet the three criteria the IAU uses to define a full-sized planet. Essentially Pluto meets all the criteria except one—it “has not cleared its neighboring region of other objects.”