Hi Rosala
TitaniumRome is correct in that the answer cannot be written down in digits and be absolutely correct.
So it comes down to the degree of accuracy
Obviously the more accuracy pi has before you square it, the more accuracy the square will have.
$${\mathtt{\pi}} = {\mathtt{3.141\: \!592\: \!653\: \!589\: \!793\: \!2}}$$
is a closer approximation than $$3.14$$
So when you square it the answer will also be more accurate.