Wht is the result of 54×18 written in standard form ​

Mindy bought 5/8 pound of almonds and a 3/4 pound of walnuts.which pair of fraction cannot be used to find how many pounds of nuts she bought in all.

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?

Can someone answer this question? : )