Given a square ABCD and an equilateral triangle DPC and given a chart with which Jim is using to prove that triangle APD is congruent to triangle BPC.
From the chart, it can be seen that Jim proved that two corresponding sides of both triangles are congruent and that the angle between those two sides for both triangles are also congruent.
Therefore, the justification to complete Jim's proof is "SAS postulate"
Nothing can go into 83 so of you square root it you will get a decimal so the nearest whole number You would get is 9 because 9*9=81 and that's the closet that you will get to 83