Question

a square piece of paper of side 12cm is rolled to form of a cylinder . find the curved surface of area of the cylinder

Answer 1

Side =12 cm So 2 pie r = 12 cm 2 pie r =12 Pie r = 6 cm r= 6 ×7÷22 r = 21/11 CSA of cylinder = 2 pie rh 2 pie rh =2×22/7 ×21/11×12 = 144 cm ^2

Answer 2

 Circumference of the base circle = 2 x pi x r =12cm
 Height of the cylinder = 12 cm
 C.S.A of a cylinder  = 2 x pi x r x h
                                  = (2 x pi x r) x h
                                  =12 x 12
                                  = 144 sq cm.