Question

diameter of base of cone is 10.5 en and slant
height is 10cm. find csa of cone

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Answer 1

Appropriate Quesiton :

Diameter of base of cone is 10.5 cm and slant height is 10cm. find CSA of cone.

Given :

• Diameter of base of cone = 10.5 cm
• Slant height of the cone = 10 cm

To find :

• Curved surface area of cone

Knowledge required :-

• Formula to calculate radius :-

⠀⠀⠀⠀⠀Radius = Diameter/2

• Formula to calculate CSA of cone :-

⠀⠀⠀⠀⠀CSA of cone = πrl

where,

• Take π = 22/7
• r = radius
• l = slant height

Solution :

Firstly, we will calculate radius of the cone.

⠀⠀⠀⇒ Radius = Diameter/2

⠀⠀⠀⇒ Radius = 10.5/2

⠀⠀⠀⇒ Radius = 5.25

• Radius of the cone = 5.25 cm

Now, we will calculate the CSA of cone.

⠀⠀⠀⇒ CSA = πrl

⠀⠀⠀⇒ CSA = 22/7 × 5.25 × 10

⠀⠀⠀⇒ CSA = 22/7 × 525/100 × 10

⠀⠀⠀⇒ CSA = 22/7 × 525/10

⠀⠀⠀⇒ CSA = 22 × 75/10

⠀⠀⠀⇒ CSA = 1,650/10

⠀⠀⠀⇒ CSA = 165

Curved surface area of cone = 165 cm²

Answer 2

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Given :

Diameter of base of cone = 10.5 cm

Slant height of the cone = 10 cm

To find :

Curved surface area of cone

Knowledge required :-

Formula to calculate radius :-

⠀⠀⠀⠀⠀Radius = Diameter/2

Formula to calculate CSA of cone :-

⠀⠀⠀⠀⠀CSA of cone = πrl

where,

Take π = 22/7

r = radius

l = slant height

Solution :

Firstly, we will calculate radius of the cone.

⠀⠀⠀⇒ Radius = Diameter/2

⠀⠀⠀⇒ Radius = 10.5/2

⠀⠀⠀⇒ Radius = 5.25

Radius of the cone = 5.25 cm

Now, we will calculate the CSA of cone.

⠀⠀⠀⇒ CSA = πrl

⠀⠀⠀⇒ CSA = 22/7 × 5.25 × 10

⠀⠀⠀⇒ CSA = 22/7 × 525/100 × 10

⠀⠀⠀⇒ CSA = 22/7 × 525/10

⠀⠀⠀⇒ CSA = 22 × 75/10

⠀⠀⠀⇒ CSA = 1,650/10

⠀⠀⠀⇒ CSA = 165

Curved surface area of cone = 165 cm²

Hence required answer is 165 ✔