<span>Two geometic shapes are congruent if one can be mapped to the other only by using rigid motions: translations and rigid rotations. The third statement is the only one that is true for any triangles â–łPQR and â–łXYZ, in whichever position they are.</span>
Answer: <em>(1,5,7,10,11,15)</em>
To get the union of two sets of numbers, all you do is combine the numbers from least to greatest. If a number repeats in the 2 sets, you only put it once.