COMEDK2024MathematicsPermutation and Combination
If a n -sided polygon has total 54 diagonal then the value of n is
Options
- A10
- B11
- C12
- D13
Correct answer
C. 12
Step-by-step solution
Number of diagonal in n -sided polygon array ll & = n(n-3) 2 & n(n-3) 2 =54 & n^2-3 n=108 & n^2-3 n-108=0 & n=12 or n=-9 array