Question 951978

ABC is acute triangle. Forget about that. The important thing here is the two sides: {{{11cm}}} and {{{14cm}}}.
 
recall: in any triangle one side has to be  less than the sum other two sides; so, the 3rd side has to be less than   {{{14cm+11cm=25cm}}} and has to be greater than the difference  {{{14cm-11cm = 3cm}}}  (you can't do {{{11-14}}} because sides of triangle are always positive)
Now we know that the third side can be anything between {{{3cm}}} and {{{25cm}}}.

your answer is: {{{3cm<x<25cm}}}