Multiple choice general knowledge math & puzzles

How many sides a circle of radius R have?

  1. 2 TT R

  2. TT R*R

  3. 2 TT R*R

  4. none of these

Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

In Euclidean geometry, a circle is defined as a smooth curve with no straight sides (or infinitely many infinitesimal sides). None of the provided formulas (circumference or area) represent the 'number of sides'.