Multiple choice

The height of the right circular cone is 5 cm and its base radius is 12 cm. What is curved surface area of the cone ?

  1. 132πcm2

  2. 143 πcm2

  3. 156 πcm2

  4. 168 πcm2
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

For a right circular cone with height h = 5 cm and base radius r = 12 cm, first find the slant height l using Pythagoras theorem: l = √(h² + r²) = √(25 + 144) = √169 = 13 cm. The curved surface area is πrl = π × 12 × 13 = 156π cm². Option A incorrectly uses l = 11, giving 132π. Option B uses incorrect dimensions.

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