Multiple choice

The total surface area of a hemisphere of radius r is given by

  1. $ \displaystyle 2\pi r^{2} $
  2. $ \displaystyle \pi r^{2} $
  3. $ \displaystyle 3\pi r^{2} $
  4. $ \displaystyle 4\pi r^{2} $
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C Correct answer
Explanation

A hemisphere has a curved surface area of 2*pi*r^2 and a flat circular base of pi*r^2. Total surface area = 3*pi*r^2.

AI explanation

A hemisphere has a curved surface area given by the formula 2 times pi times r squared. To find the total surface area, you must add the flat circular base, whose area is pi times r squared. Adding these two parts together gives 2 times pi times r squared plus pi times r squared, which equals 3 times pi times r squared.