Question

The volume of right circular cone is 2200 cm and its height 12 cm. Find its slant
height.
7
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Answer 1

Correct Question:

• The volume of right circular cone is 2200/7 cm and its height 12 cm. Find its slant height.

Given:

• Volume of circular cone = 2200 cm
• Height of cone = 12 cm

To find:

• Slant height of cone?

Solution:

We know that,

Volume of cylinder = 1/3 πr²h

⇒ 2200/7 = 1/3 × 22/7 × r² × 12

⇒ 2200/7 = 264r²/21

⇒ r² = 2200/7 × 21/264

⇒ r² = 25

⇒ √r² = √25

⇒ r = 5 cm

∴ Radius of cone is 5 cm.

Now, Finding slant height of cone,

We know that,

l = √h² + r²

⇒ l = √12² + 5²

⇒ l = √144 + 25

⇒l = √139

⇒ l = 13 cm

∴ Hence, Slant height of cone is 13 cm.