Hello i really need help

You are assembling pieces of an iron gate to complete a fence. the finished gate will look like the one below. in order to assemble the gate it is important to under how the pieces are related. part 1: how are pies 1 and 2 in the archway related? part 2: how are the rectangular sections 5 and 6 in the center of the gate related to each other?

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?

If f(x) = 3x2 - 2x+4 and g(x) = 5x + 6x - 8, find (f-g)(x).