Question

The area of the iron sheet required to prepare a cone without base of height 3cm with radius 4cm is

Answer 1

Answer:

8 centimeters

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Answer 2

Step-by-step explanation:

$\large\underline{ \underline{ \sf \maltese{ \: Correct \: Question:- }}}$

Find the area of iron sheet required to prepare a cone without base of height 3 cm with a radius 4cm.

$\large\underline{ \underline{ \sf \maltese{ \: Given:- }}}$

Cone formed with the iron sheet is without base.

Height of cone: 3cm

Radius of cone: 4cm

$\large\underline{ \underline{ \sf \maltese{ \: To\:Find:- }}}$

Area of Iron sheet required to form the cone i.e CSA of cone

$\large\underline{ \underline{ \sf \maltese{ \: Solution:- }}}$

Slant height of the cone: l² = r² + h²

$\sf{\implies}{l^2=4^2+3^2}$

$\sf{\implies}{l^2=16+9}$

$\sf{\implies}{l^2=25}$

$\sf{\implies}{l= {\sqrt{25}}}$

$\sf{\green{\implies}}{\green{l=5cm}}$

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Now, for the CSA of the cone: πrl

$\sf{CSA=3.14\times 4\times 5}$

$\sf{CSA=3.14\times 20}$

$\sf{\red{CSA=62.8cm^2}}$

Therefore, a iron sheet of area 62.8cm² is required to form a cone with radius 4cm and 3cm.

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Some formulas related to SA and Volume.