Respuesta :

The perimeter of a rectangle is twice the sum of the dimensions:

[tex] 2p = 2(w+l) [/tex]

We know two of the three unkowns, so we can solve for w:

[tex] 78 = 2(w+34) \iff 78 = 2w+68 \iff 10=2w \iff w=5 [/tex]