The true value of the perimeter lies between 27.22 cm and 27.26 cm. So we obviously can't be sure what the value of the second decimal place is: it's somewhere between 2 and 6, inclusive.
Can we instead give the value of the perimeter correct to 1 d.p.?
Well, correct to 1 d.p:
27.22 is 27.2;and
27.26 is 27.3.
So the perimeter might be either 27.2 or 27.3, correct to 1 d.p.
So, no, we can't give the value to 1 d.p. and be sure of getting it right.
What about giving the value to the nearest whole number?
When we round 27.22 and 27.26 to the nearest whole number, each one is 27. So we can be sure that, correct to the nearest whole number, the perimeter is 27 cm.
Is that OK now?