Two sides of an obtuse triangle measure 12 inches and 14 inches. the longest side measures 14 inches. what is the greatest possible whole number length of the unknown length of the unknown side

The length of a side of a triangle must be less than the sum of the lengths of the other two sides and greater than the difference of the lengths of the other two sides.

12 in. + 14 in. = 26 in.

14 in. - 12 in. = 2 in.

The third side must measure more than 2 inches and less than 26 inches, but we are told that the 14-inch side is the longest side of the triangle, so the third side must measure less than 14 inches. The largest whole-number length less than 14 inches is 13 inches.

It measures 13 inches.