Question 989303
w, width of the frame.
{{{system(2*13+2*20=p,2(13+2w)+2(20+2w)=98)}}}
You only need the second of these equations.


{{{13+2w+20+2w=49}}}
{{{4w+33=49}}}
{{{4w=16}}}
{{{w=4}}}