Multiple choice

If the radius of a sphere is doubled, its surface area becomes

  1. 2 times

  2. 8 times

  3. 4 times

  4. 16 times
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

The surface area of a sphere is 4 * pi * r^2. If r becomes 2r, the new area is 4 * pi * (2r)^2 = 4 * pi * 4r^2 = 16 * pi * r^2, which is 4 times the original area.

AI explanation

The surface area of a sphere is given by the formula 4 * pi * r^2. If the radius is doubled, the new radius becomes 2r, making the new surface area 4 * pi * (2r)^2, which expands to 16 * pi * r^2. Comparing the new surface area to the original shows it becomes exactly 4 times larger.

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