Why is a square root of a whole number is always a rational number?

Which fraction below is equivalent to 10/12?

Which triangle congruence postulate or theorem justifies my claim that the steps i made using construction paper and scissors produce an isosceles triangle? was it sss, sas, asa, aas, or hl?

Find the greatest common factor of -30x 4 yz 3 and 75x 4 z 2.