Good afternoon,
First side= 8cm
Third side= x
Second side= 2x-4
We know that the sume of the lenghts of any two sides must be greater than the third side, so:
[tex]Second \,\,\,\,side+Third\,\,\,\,side>First\,\,\,\,side \\ 2x-4 + x >8 \\ 3x>12 \\ x>4
[/tex]
Answer: Third side= x ; where: x>4 or (4,+infinity)
Second side= 2x-4 ; where: x>4 or (4,+infinity)