Question

Which collection of three side lengths will not form a triangle

Answer 1

Any collection of lengths (a, b, c) which do not satisfy the triangle inequalities.

Explanation:

Any collection (a, b, c) which do not satisfy the triangle inequalities. The inequalities:

a + b > c

b + c > a

a + c > b

You will need to test all of your options on the three inequalities above. If any one of the three fails, the collection won't work.