Math
posted by Simon .
A cylindrical tube is open at both ends.the internal diameter tube 10.4cm and its length is 25cm. If the thickness of the tube 8mm everywhere,find the total surface of area of the tube.

inner diameter is 10.4
outer diameter is 11.2
A = π(25)(10.4+11.2) = 540π 
Bt its ans is 1816.32cm^2

Plz help me

TOTAL SURFACE AREA =
EXTERNAL CURVED SURFACE AREA INTERNAL CURVED SURFACE AREA
in AREA OF BOTH CROSS SECTION
=2¦ÐRh 2¦Ðrh 2¦Ð{R square  r square)