Question

find the height of cylinder whose radius is 7 cm and the total surface area 968 cm square

Answer 1

TSA of cylinder = 2πrh + πr²
      968              =2*22/7*7*h + 22/7*7*7
         968           =44h + 154
       968-154      =44h
    814                =44h
        814\44        =h
          18.5        = height of cylinder
       

Answer 2

Total surface area = 2 pie r (r+h)
Therefore, total surface area = 968

2*22/7*7 ( 7+ h) = 968
2* 22(7+h) = 968
44(7+h) = 968
7+h = 968 / 44
7+h = 22
h = 22-7
h = 15

Hence , the height of the cylinder is 15cm