Multiple choice

What is the total surface area of a cone with slant height $9$ m and radius of base $6$ m?

  1. $28286$ m$\displaystyle ^{2} $
  2. $2828.6$ m$\displaystyle ^{2} $
  3. $28.286$ m$\displaystyle ^{2} $
  4. $282.86$ m$\displaystyle ^{2} $
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D Correct answer
Explanation

Total surface area of a cone = πr(r + l). r = 6, l = 9. Area = π * 6 * (6 + 9) = π * 6 * 15 = 90π. Using π = 3.14159, 90 * 3.14159 = 282.74, which is approximately 282.86.

AI explanation

The total surface area of a cone is the sum of the base area and the lateral surface area, given by the formula (pi)r(l + r). Substituting the radius of 6 m and slant height of 9 m gives an area of (22/7) times 6 times 15, which equals 282.86 square m.

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