Why can't you find the exact surface area of a cylinder?

Answer 1

S.A.(Cyl) = 2pir*h This is for the circular (round) face.

Then add the area of the two circular ends

2A = 2pir^(2)

Hence for the whole cylinder including the circular ends.

S.A. = 2pirh + 2pir^(2)

Factor

S.A. = 2pir(h + r)

So you needs to know the radius(r) and cylinder(length)(h).

The units will be squared (units^(2)).

An example

R = 2 cm

h = 20 cm

Hence

SA = 23.142(2 + 20)

SA= 23.142(22)

SA = 3.14 (88)

SA = 276.32 cm^(2).

Answer 2

because its round and it doesnt have any edges