Multiple choice

If the height and radius of a cone are 12 cm and 5 cm respectively then find its curved surface area?

  1. 214.28 cm2

  2. 204.28 cm2

  3. 325.12 cm2

  4. None of these

  5. Cannot be determined
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

The slant height l = sqrt(r^2 + h^2) = sqrt(5^2 + 12^2) = 13 cm. The curved surface area is pi * r * l = 3.14159 * 5 * 13 = 204.20 cm^2. Using 22/7 as pi gives 204.28 cm^2.

AI explanation

To find the slant height, we use the Pythagorean theorem since the square of the slant height equals the square of the radius plus the square of the height. Calculating this gives the square root of (5 squared plus 12 squared), which is the square root of 169, making the slant height 13 cm. The curved surface area of a cone formula is pi times r times l, so we compute 22 over 7 times 5 times 13, yielding 204.28 cm2.

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