Multiple choice

Find the total surface area of the cone of height 4 cm and radius 3 cm. (π = 3.14)

  1. 73.12 cm2

  2. 74.24 cm2

  3. 75.36 cm2

  4. 76.48 cm2

  5. 78.48 cm2
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

Slant height l = sqrt(r^2 + h^2) = sqrt(3^2 + 4^2) = 5 cm. Total Surface Area = pi * r * (r + l) = 3.14 * 3 * (3 + 5) = 3.14 * 3 * 8 = 75.36 cm^2.

AI explanation

Using the Pythagorean theorem, the slant height is the square root of (4 squared plus 3 squared), which equals 5 cm. The total surface area of a cone is found by adding pi times r times l to pi times r squared. Substituting the values gives 3.14 times 3 times 5 plus 3.14 times 3 squared, resulting in 47.1 plus 28.26, which equals 75.36 sq cm.

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