Check all apply -x-3=-7

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?

In the diagram below,abc is congruent to dec what is the value of x

What are the coordinates of the image of p for a dilation with center (0, 0) and scale factor 2