Please help explanation if possible

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?

Iwill make brain if you me correctly fill this out needs due today pls and send it back to me (click the link and you will get it)

Find the roots of the equation below. x^2 - 6 + 9 = 0