1.Cut Lining Sheet To square that fits the round pan

 2.Fold it in half.
 3.Then again in half.
 4.Then further in half
 5.Then again in half.
 6.Place the paper on pan and mark the length and cut  the paper straight at the marked point .Now if u open it will be round that fits the pan.
 7.Grease the pan

 8.Place the lining sheet.Now you got a perfect round cut