Question

A square piece of paper of side 12 cm is rolled to form a cylinder. find its C.S.A

Answer 1

side forms its circumference.
2Πr^2=12
r^2=42÷11
r=√3•81
r=1•95
CSA=2Πrh
=2×22÷7×1•95×12
=147•09

Answer 2

since the cylinder is made of square paper so
CAS of cylinder = area of sqaure sized paper
                          =12*12
                          =144 cm. sq.