Question

Harsh has a cylindrical pen stand of radius 7cm and height 15cm
He wants to cover its curved surface with colour paper.What is the area that has to be covered?​

Answer 1

Step-by-step explanation:

EDITING

The following passages have not

een edited. There is one error in each line.

Find the errors. Underline them and write the correct word.

1. Ordinary good looks depend on one's sense

of humour 'a

merry heart has its cheerful

and

countenance Joyfulness keeps the heart

but face

young. Laughter helps us to become better friends to

ourselves and others with whom we interact.

It was worthwhile being happy.

d.

The sympathetic nerves are close connected: when one

set of nerves carries bad news with the head, the nerves f.

reaching the stomach is affected and indigestion

makes ones miserable and doleful.

h.

6

Answer 2

Find the radius of the cylinder:

Radius = Diameter ÷ 2

Radius = 7 ÷ 2 = 3.5 cm

Find the surface area of the cylinder:

Surface area = 2πr² + 2πrh

Surface area = 2π(3.5)² + 2π(3.5)(15) = 407 cm²

Find the slanted height of the conical hole:

a² + b² = c²

c² = 3² + 4²

c² = 3² + 4²c² = 25

c² = 3² + 4²c² = 25c = √25

c² = 3² + 4²c² = 25c = √25c = 5 cm

Find the area of the base of the cone:

Area = πr²

c² = 3² + 4²c² = 25c = √25c = 5 cm

Find the area of the base of the cone: Area = πr²Area = π(3)² = 198/7 cm²Find the curved surface area of the cone:

= πr²Area = π(3)² = 198/7 cm²Find the curved surface area of the cone:Area = πrl

total surface area:Total Surface area = Total Surface area of cylinder - 2(base of the cone) + 2(curved surface area of the cone)Total Surface area = 407 - 2(198/7 ) + 2(330/7) = 444.71 cm²Answer: Total Surface area = 444.71 cm²