Question

2.The curved surface area of cylinder is 1980 CM² and the radius of its base is 15cm. Find the

height of the cylinder (.(π= 3.14))​

Answer 1

Let's understand the question.

★ This question says us to find out the height of the cylinder, and we are given with the curved surface area of cylinder and radius of it's base of cylinder, so by using the formula of curved surface area (CSA) of cylinder we can easily find out the height of the cylinder$.$

Let's solve the problem now!

Given that,

• CSA of cylinder = 1989cm².

• Radius of it's base = 15cm.

And, we need to find out the height of the cylinder.

Let's consider the height of the cylinder is h cm.

We know that, if we are given with curved surface area of cylinder and radius of it's base, then we have the required formula, that is,

• CSA of cylinder = 2πrh.

By using the formula to calculate the height of cylinder, and substituting all the given values in the formula, we get :

➝ 1980 = 2 × 3.14 × 15 × h

➝ 1980 = 6.28 × 15 × h

➝ 1980 = 94.2 × h

➝ 1980 = 94.2h

➝ h = 1980/94.2

➝ h = 21.01 (Ans.)

Hence, the height of the cylinder is 21.01cm.

Additional information :

Some related formulas:

• Volume of cylinder = πr²h
• T.S.A of cylinder = 2πrh + 2πr²
• Volume of cone = ⅓ πr²h
• C.S.A of cone = πrl
• T.S.A of cone = πrl + πr²
• Volume of cuboid = l × b × h
• C.S.A of cuboid = 2(l + b)h
• T.S.A of cuboid = 2(lb + bh + lh)
• C.S.A of cube = 4a²
• T.S.A of cube = 6a²
• Volume of cube = a³
• Volume of sphere = 4/3πr³
• Surface area of sphere = 4πr²
• Volume of hemisphere = ⅔ πr³
• C.S.A of hemisphere = 2πr²
• T.S.A of hemisphere = 3πr²

Answer 2

Answer:

Given :-

• The curved surface area of cylinder is 1980 cm² and the radius of its base is 15 cm.

To Find :-

• What is the height of the cylinder.

Formula Used :-

$\longmapsto \sf\boxed{\bold{\pink{Curved\: Surface\: Area\: Of\: Cylinder =\: 2{\pi}rh}}}$

where,

• r = Radius
• h = Height

Solution :-

Let, the height of the cylinder be h cm

Given :

• Curved surface area = 1980 cm²
• π = 3.14
• Radius = 15 cm

According to the question by using the formula we get,

$\implies \sf 2 \times 3.14 \times 15 \times h =\: 1980$

$\implies \sf 2 \times \dfrac{314}{100} \times 15 \times h =\: 1980$

$\implies \sf \dfrac{628}{100} \times 15 \times h =\ 1980$

$\implies \sf \dfrac{9420}{100} \times h =\: 1980$

$\implies \sf h =\: \dfrac{1980 \times 100}{9420}$

$\implies \sf h =\: \dfrac{19800\cancel{0}}{942\cancel{0}}$

$\implies \sf h =\: \dfrac{\cancel{19800}}{\cancel{942}}$

$\implies \sf\bold{\red{h =\: 21.01\: cm}}$

$\therefore$ The height of the cylinder is 21.01 cm.