Doug C. answered 8d
Math Tutor with Reputation to make difficult concepts understandable
The answer is one.
First of all given 3 segment lengths, in order to have a triangle at all: the sum of any two sides must be greater than the 3rd side.
7+11 > 13
7+13 > 11
11 + 13 > 7
The video shows a Desmos graph to help convince that there is only one such triangle.
desmos.com/calculator/t2ekhocvck