Which polygons have at least one pair of parallel sides but are not parallelograms

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?

An appliance store sells a washer-dryer combination for $1800. if the washer costs $300 more than the dryer, find the cost for each appliance.

Bring the fraction a/a-4 to a denominator of 16-a^2