We can not construct a triangle that has sides length 2 inches, 3 inches and 6 inches. It is because of the triangle inequality rule.
The triangle inequality rule states that all pairs of the values should be greater than the other side.
So for example 2 + 6 is greater than 3, similarly 3 + 6 is greater than 2, but 2 + 3 is not greater 6 so we can not construct a triangle with these sides as it does not obeys the triangle inequality rule.
I hope that this answer helps.