Question

A triangle has two sides of lengths 7 and 12 what value could the third side be?

Answer 1

-- The third side must be more than 5, otherwise it could never reach
between the ends of the 7 and the 12.

-- The third side must be less than 19, otherwise the 7 and the 12
could not reach its ends.

5 < the third side < 19 .