Cylinder : A solid generated by the revolution of a rectangular about one of its sides is called a right circular cylinder.

If we take a number of circular sheets and stake them up vertically , we get right circular cylinder.

Formulas needed for Surface Area of Cylinder :

Lateral Surface Area (LSA or CSA) = 2π r h Area of base = π r ^{2}Total Surface Area = TSA = 2 π r ( r + h) |

Lateral Surface Area (LSA or CSA) = 2π r h + 2 π R h Area of base = π ( R ^{2}- r^{2})Total Surface Area = TSA = 2 πR h + 2π rh + 2 π( R ^{2}- r^{2}) |

1) The curved surface area of a right circular cylinder of height 14 cm is 88 cm

CSA = 2 π r h

88 = 2 x 3.14 x r x 14

88 = 87.92 r = 88 r

∴ r = 1 cm

Diameter = d = 2r

d = 2 x 1 = 2 cm

_________________________________________________________________

2) The ratio between the CSA and TSA of a right circular cylinder is 1:2. Find he ratio between the height and radius of the cylinder.

TSA = 2 π r ( r + h)

CSA = 2 π r h

∴ CSA / TSA = 2 π r h / 2 π r ( r + h)

⇒ ½ = h / ( r + h )

2h = r + h

h = r

⇒ h : r = 1 : 1

_________________________________________________________________

3) An iron pipe 20 cm long has exterior diameter equal to 25 cm. If the thickness of the pipe is 1 cm, find the whole surface of the pipe.

D = 25 cm ⇒ R = 12.5 cm

r = R – thickness = 12.5 – 1 = 11.5 cm

h = 20 cm

TSA of the pipe = 2 πR h + 2π r h + 2 π( R

= 2 x 3.14 x 12.5 x 20 + 2 x 3.14 x 11.5 x 20 + 2 x 3.14 ( 12.5

= 1570 + 1444.44 + 6.28 ( 156.25 – 132.25 )

= 3014.4 + 148.8

TSA = 3163.2 cm

• Surface Area of Cube

• Surface Area of Rectangular Prism(Cuboid)

• Surface Area of Cylinder

• Surface Area of Cone

• Surface Area of Sphere and Hemisphere

• Surface Area of Prism

• Surface Area of Pyramid

8th grade math

Home Page

GMAT

GRE

1st Grade

2nd Grade

3rd Grade

4th Grade

5th Grade

6th Grade

7th grade math

8th grade math

9th grade math

10th grade math

11th grade math

12th grade math

Precalculus

Worksheets

Chapter wise Test

MCQ's

Math Dictionary

Graph Dictionary

Multiplicative tables

Math Teasers

NTSE

Chinese Numbers

CBSE Sample Papers