What is the mean absolute deviation (mad) of the data set?

{5, 9, 9, 11, 16}

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?

Given the points a(-2, 1) and b(8, 6), find the coordinates of the point c on directed line segment ab, that partitions ab in the ration 2: 3.

Which of these triangle pairs can be mapped to each other using two reflections?