Answer :
I would set this up as a a proportion:
[tex] \frac{17cm}{5cm} [/tex] · [tex] \frac{272cm}{x} [/tex]
17x = 1360
x = 20 cm
[tex] \frac{17cm}{5cm} [/tex] · [tex] \frac{272cm}{x} [/tex]
17x = 1360
x = 20 cm