The radii of end of a frustum are 14cmand 7cm respectively, it's slant height is 21 cm .Find curved surface area
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Given:
The radii of ends of a frustum are 14cm and 7cm.
Slant height of frustum is 21cm.
Find:
The curved surface area of the frustum.
Solution:
Let the radius of one end of frustum be 'R' and radius of another end be 'r'.
We know that,
Curved surface area of the frustum = π(R + r)
=> 22/7 × 21 (14 + 7)
=> 22 × 3 × 21
=> 66 × 21
=> 1386cm²
Hence, the CSA of the frustum is 1386cm².
Important Information:
- Curved Surface Area and Total Surface Area of the Frustum
- The curved surface area of the frustum of the cone = π(R+r)l1
- The total surface area of the frustum of the cone = π l1 (R+r) +πR2 +πr2
- The slant height (l1) in both the cases shall be = √[H2 +(R-r)2]
I hope it will help you.
Regards.
Answered by
1
Answer:
=> 22/7 × 21 (14 + 7)
=> 22 × 3 × 21
=> 66 × 21
=> 1386cm²
Hence, the CSA of the frustum is 1386cm².
Step-by-step explanation:
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