Question

Which set of three segments can form a triangle?

Answer 1

one millimeter, two millimeters, three millimeters

five millimeters, eight millimeters, ten millimeters

twelve millimeters, three millimeters, fifteen millimeters

two millimeters, fourteen millimeters, eighteen millimeters

Answer 2

The triangle inequality says that any two sides of a triangle must be greater than the third side.

Answer 3

to form a triangle the sum of all the possible pairs of sides must be greater than the third side

Answer 4

In practice, you only have to check that the sum of the two smaller sides is greater than the longest side. If it is satisfied, you have a triangle.

Answer 5

There is only one set out of the list that satisfies the requirement. \
Can you spot it?