Answer:
{5,16,21}
Step-by-step explanation:
sides of triangle: the sum of every two sides must be greater than the third sides.
{14,28,39}
=> 14 + 28 > 39, 14 + 39 > 28, 28 + 39 > 14 (correct)
{4,16,19}
=> 4 + 16 > 19, 4 + 19 > 16, 16 + 19 > 4 (correct)
{4,11,13}
=> 4 + 11 > 13, 4 + 13 > 11, 11 + 13, > 4 (correct)
{5,16,21}
5 + 16 not > 21 (wrong)
