Question

Find the curved surface area of a cone whose area of the base and height are 154 cm sq. and 24 cm,respectively.

Answer 1

Answer:

Find the curved surface area of a cone whose area of the base and height are 154 cm sq. and 24 cm,respectively.

Step-by-step explanation:

Answer 2

Given :-

➤ Area of the base of a right circular cone = 154 cm²

Find :-

Curved surface area = ?

Solution :-

We know the formula :- πr²

➤ πr² = 154 cm²

⇒ (22/7) × r² = 154

⇒ r² = 154 × (7/22)

⇒ r² = 7 × 7

⇒ r² = 7²

⇒ r = 7

Now , we got the radius of the base = 7 cm

Therefore , then

As we all know , = l² = h² + r²

So we consider the slant height be l cm.

l² = h² + r²

⇒ l² = (24)² + (7)²

⇒ l² = 576 + 49

⇒ l² = 625

⇒ l² = 25²

⇒ l = 25

$Now$ Slant height is 25 cm

So C.S.A of cone = πrl

➤ (22/7) × 7 × 25

➤ 22 × 1 × 25

➤ 22 × 25

➤ 550 cm ²

Hence ,

Curved surface area is 550 cm²

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