Question

Two sides of a triangle measures 24 inches and 29 inches. which of the following lengths could represent the 3rd side?

Answer 1

When 2 triangle sides are known, the third side must be:
Greater than the Difference of the other 2 sides and
Less than the SUM of the other 2 sides
Difference = 5
Sum = 53
So, the sides that fit this requirement are 7 and 31.

Source:
http://www.1728.org/trianinq.htm