Question

1) I have made a closed right circular cone whose length of the base radius is 15 cm. and slant height is 24cm. Let us calculate the curved surface area and total surface area of that cone.​

Answer 1

Solution :

For a closed right circular cone :

• Radius of cone is 15 m .

• Slant height of cone is 24 cm .

Now , we know that :

Curved Surface Area of a cone :

> π r l

=> π × 15 × 24

=> 22/7 × 15 × 24

≈ 1131 cm²

Total surface area of a cone :

> π r ( l + r )

> 22/7 × 15 × ( 24 + 15 )

> 22/7 × 15 × 39

≈ 1838 cm² .

This is the required answer .

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Additional Information :

For a cone having a base radius r, height h and a slant height l

• l = √{ h² + r² }

• Volume = ⅓ π r² h

• CSA = π r l

• TSA = π r l + π r² = π r( l + r)

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Answer 2

Answer:

Given :-

• Radius of base of the cone = 15 cm
• Slant height = 24 cm

Find Out :-

• Curved surface area
• Total surface area

Solution :-

To find curved surface areas we know that,

▶ $Curved\: surface\: area\: =\: {\pi}rl$

By substituting the formula we get,

⇒ $\dfrac{22}{7} \times 15 \times 24$

⇒ $\dfrac{22}{7} \times 360$

➠ 1131.43 sq cm.

Hence, the curved surface area is 1131.43 sq cm.

Again, to find total surface area we know that,

▶ $Total\: surface\: area =\: {\pi}r(r + l)$

By substituting the formula we get,

➛ $\dfrac{22}{7} \times 15(15 + 24)$

➛ $\dfrac{22}{7} \times 15(39)$

➛ $\dfrac{22}{7} \times 585$

➦ 1838.57 sq cm.

Hence, the total surface area is 1838.57 sq cm.