Which of the following sets of possible side lengths does not form a triangle? 22, 21, 42
3, 4, 5
5, 6, 10
4, 5, 15

Step-by-step explanation:

4 ,5 ,15 cannot form a triangle

In order to form a triangle the sum of length of the the two sides should exceed the third side so here

4+5 > 15

9 > 15 ( False)

5+15> 4

20> 4 ( True)

15 + 4> 5

19> 5 (True)

Here it should all be true here so it can't form a triangle.

Hope it will help :)