Question

A jokers cap is in the form of right circular cone of base radius 7cm and height 27cm find the area of the sheet required to make 10 caps

Answer 1

Solution :-

Curved Surface Area of Cone = πrl

Given - Height = 27 cm and Radius = 7 cm

l (Slant height) = √h² + r²

⇒ l = √27² + 7²

⇒ l = √729 + 49

⇒ l = √778

⇒ l = 27.89

Now,

CSA of Cone = πrl

⇒ 22/7*7*27.89

⇒ 613.58 cm²

So, the area of sheet of cloth is 613.58 cm² to make a cap.

For making 10 such caps, area of sheet of cloth needed = 613.58*10

= 6135.8 cm²

Answer.

Answer 2

Given :

Radius(r) = 7 cm

Height (h)= 27 cm

Slant height(l) = √h² + r²

l = √27² + 7²

l = √729 + 49

l = √778


l = 27.89 cm

Now,

Curved surface area of a joker's cap = curved surface area of Cone = πrl

= (22/7) × 7× 27.89

Curved surface area of a joker's cap = 613.58 cm²


The sheet required to make 1 cap = 613.58 cm²

The sheet required to make 10 such caps = 613.58×10 = 6135.8 cm²

Hence, The sheet required to make 10 such caps is 6135.8 cm².

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Hope this will help you...