Why is the square root of a perfect square always rational

A perfect square by defenition is a numer that is a result of squareing a whole number

so since y ou sqare root a perfect square, the square root and squared cancel and you are left with awhole number

ration numbers can be written in the form a/b where b is not equal zero so 5=5/1 and isi therefor rational
all whole numbers are rational numbers, so therefor all square roots of perfect squares are always rational
example
25=5^2 
square root of 25=5
rational

the law of definite proportions states samples of a compound will always contain the same proportion of elements by mass. in other words, a given compound will always contain the same elements in the same proportions by mass.the law of multiple proportions states when two elements combine with each other to form more than one compound, then the weights of one element that combine with a fixed weight of the other are in a ratio of small whole numbers.