# Volume and SA of a cylinder.

#### thierryvoomhenry

i have a cylinder here i need to find the volume and the surface area

the cylinder is 4cm base height 15cm

would the volume be 3.14 x 42 x 15 = 753.6 i have to give the answer to 3 significant figures so 754cm.

and would the surface area be

2 x 3.14 x 4 x 15 + 2 x 3.14 x 42 = 194.68 i have to give the answer to 2 siginificant figures so 190cm!

is that right?????

Last edited by a moderator:

#### Sudharaka

i have a cylinder here i need to find the volume and the surface area

the cylinder is 4cm base height 15cm

would the volume be 3.14 x 42 x 15 = 753.6 i have to give the answer to 3 significant figures so 754cm.

and would the surface area be

2 x 3.14 x 4 x 15 + 2 x 3.14 x 42 = 194.68 i have to give the answer to 2 siginificant figures so 190cm!

is that right?????
Dear thierryvoomhenry,

The volume is correct. But you should better check the surface area. It should be, 477.28

#### unstopabl3

Hmmm, I am pretty sure the formulas are as following: Therefore, the correct volume is 188.496 or 188 (3 sig figures) and the correct surface area is 213.628 or 214 (3 sig figures)

I think both of your are taking the radius as 4 cm whereas that's the length of the base, which can be used as a diamter but half that is the radius of that cylinder.

Hope this helps!

Last edited:
• Sudharaka

#### Sudharaka

Dear unstopabl3,

Yes you are correct. When he says "the cylinder is 4cm base" it is most probably the diameter.