Question

diameter of the base of a cone is 10.5 cm and it is salent height is 20 cm . find the corved surface area​

Answer 1

Sᴏʟᴜᴛɪᴏɴ :-

→ Diameter of base of cone = 10.5cm.

→ Slant height of cone = 20cm.

→ CSA = π * (radius of base) * slant Height .

→ Radius of base = (Diameter)/2

Putting all values we get :-

→ CSA = (22/7) * (10.5/2) * 20

→ CSA = (22/7) * 10.5 * 10

→ CSA = (22/7) * 105

→ CSA = 22 * 15

→ CSA = 330cm². (Ans.)

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Extra :-

→ Total surface Area of cone = πrl + πr² = CSA + Area of base.

→ Volume of cone = (1/3) * π * (radius)² * Height.

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Answer 2

$\mathcal{\huge{\underline{\underline{\red{Question}}}}}$

⬛ The Diameter of the base of a cone is 10.5 cm and it is salent height is 20 cm . Find the curved surface area .

$\mathcal{\huge{\underline{\underline{\green{Answer:-}}}}}$

✏ The curved surface area is 330cm².

$\mathcal{\huge{\underline{\underline{\pink{Solution:-}}}}}$

Given :-

• The diameter of the base = 10.5 cm

So, r = $\dfrac{d}{2}$

• r = $\dfrac{10.5}{2}$

• Salent height = 20 cm

To Find :-

↗ The Curved Surface Area

Formula Used :-

$\mathcal{\huge{\fbox{\fbox{\orange{CSA\:=\:π\:r \:l}}}}}$

Calculation :-

CSA = π × radius of base × slant Height

➡ CSA = $\dfrac{22}{7}$ × $\dfrac{10.5}{2}$ × 20

➡ CSA = $\dfrac{22}{7}$ × 10.5 × 10

➡ CSA = $\dfrac{22}{7}$ × 105

➡ CSA = 22 × 15

➡ CSA = 330cm²

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