Is there a picture of the problem I can help
The diagram shows statements to prove that both triangles are congruent.
Hence;



Step 1 showed two sides that are congruent for both triangles
Step 2 showed two angles that are congruent
Step 3 showed two sides that are congruent
Therefore, the triangles are congruent by the side-angle-side theorem
Since you technically didn't ask for anything to be solved for, this problem is now solved. Since these types of problems are normally solving for legnth if width is given and vice versa, I will solve for legnth.
perimiter=legnth+legnth+width+width or
p=l+l+w+w
p=2l+2w
subsitute w=6.5 and p=34
34=2l+2(6.5)
34=2l+13
subtract 13 from both sides
21=2l
divide by 2
10.5=l
legnth=10.5 units