Perimeter of a triangle=sum of all sides.
We have three sides in a triangle;
The third side is : x
The second side is:2x
The first side is : 2x+4
Then we have the following equation.
x+2x+(2x+4)=44
5x=40
x=40/5
x=7
The third side is x=8
The second side is 2x=2*8=16
The first side is: 2x+4=2*8+4=20
The sides of the triangle would be: 8 cm, 16 cm and 20 cm