Add the sides together:
[tex] perimeter = \frac{7}{8} + \frac{7}{8} + \frac{3}{5} + \frac{3}{5} [/tex]
simplify:
[tex] = \frac{7}{4} + \frac{6}{5} = \frac{7}{4} \times \frac{5}{5} + \frac{6}{5} \times \frac{4}{4} [/tex]
[tex] = \frac{35}{20} + \frac{24}{20} = \frac{59}{20} [/tex]
Answer is
[tex] \frac{59}{20} = 2.95cm[/tex]