Multiple choice

An equilateral triangle of side 9 cm is inscribed in a circle. Find the radius of the circle.

  1. $3 \sqrt{3}$ cm
  2. $3 \sqrt{2}$ cm
  3. $2 \sqrt{3}$ cm

  4. None of these
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A Correct answer
Explanation

For an equilateral triangle with side 'a', the circumradius R = a / sqrt(3). Here a = 9, so R = 9 / sqrt(3) = 3 * sqrt(3).

AI explanation

For an equilateral triangle with side length s inscribed in a circle, the radius of the circumscribed circle is given by the formula r = s / sqrt(3). Substituting the given side length of 9 cm into the formula yields 9 / sqrt(3). Rationalizing this value gives the radius as 3 * sqrt(3) cm.

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