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MHT CET202314 May 2023Evening ShiftMathematicsPermutation and CombinationActual

If in a regular polygon, the number of diagonals are 54 , then the number of sides of the polygon are

Options

  1. A10
  2. B12
  3. C9
  4. D6

Correct answer

B. 12

Step-by-step solution

Number of diagonals in a polygon of n sides is ^ n C ₂- n . aligned & ^ n C ₂- n =54 & n ( n -1) 2 - n =54 & n ^2-3 n -108=0 & ( n -12)( n +9)=0 aligned But, number of sides cannot be negative. n =12

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