I need help with the problem

Idon’t understand this.. will someone ? will mark brainliest along with 20 points.

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?

What is the solution set of the quadratic inequality x^2-5< or equal to 0