Question

The height of a cylinder is 15 cm. Its curved surface area is 660 cm2

. Find its radius.​

Answer 1

Question :

The height of cylinder is 15cm. It's Curved surface area is 660 cm². Find its radius.

Answer :

ㅤㅤ7 cm

Given :

• Height of cylinder = 15 cm
• Curved surface area of cylinder = 660cm²

To find :

• Radius of cylinder .

Solution :

Curved surface area of cylinder = 2πrh

➭ 660 = 2 × 22/7 × r × 15

➭ 660 = 44 / 7 × r × 15

➭ r = 660 × 7 / 44 × 15

➭ r = 7 cm

➫Radius of cylinder = 7cm.

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❑ Know more :

• A cylinder is a three-dimensional solid, whose circular base and top are parallel to each other.
• Total surface area of cylinder = 2πr(r+h)
• Volume of cylinder = πr²ɧ.

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Answer 2

Given :-

• Height of a cylinder is 15 cm
• Curved Surface Area ( CSA ) of cylinder is 660 cm²

To Find :-

• Radius of the cylinder

Solution :-

❒ Here , we can put the given values in the formula of CSA of a cylinder in order to find the height.

$\underline{\bf{\dag} \:\mathfrak{As\;we\;know\: that\: :}}$

$\sf \bigstar \; CSA\;of\;cylinder = 2\pi rh$

★ Where ,

• r is the radius
• h is the height .

➼ Finding the radius ::

$\sf \implies 2 \times \dfrac{22}{7} \times r \times 15 = 660$

$\sf \implies \dfrac{660}{7} \times r = 660$

$\sf \implies r = 660 \times \dfrac{7}{660}$

$\sf \implies r = 7 \; cm$

∴ Radius of the cylinder is 7 cm

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More to know :-

Base of cylinder

Each of circle ends on which cylinder rests.

Axis of Cylinder

Line segment joining centres of two circular bases

Radius of Cylinder

Radius of circular bases

Height of Cylinder

The length of axis of cylinder

Lateral Surface

The curved surface joining the two bases

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