Find the value of x in the triangle shown below

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?

The reflexive property of congruence lets you say that ∠pqr ≅

If on=8x-8,lm=7x+4,nm=x-5,and ol=3y-6