99 Percentile Qs Bank for JEE MainMathematicsPermutation and Combination
A polygon has 44 diagonals. Then the number of sides of the polygon are
Options
- A11
- B12
- C10
- D13
Correct answer
A. 11
Step-by-step solution
Number of diagonals of ' n ' sided polygons = ^n C₂-n aligned & ^n C₂-n=44 & n ! 2 !(n-2) ! -n=44 n(n-1)-2 n=88 & n^2-3 n-88=0 (n-11)(n+8)=0 & n=11 [n N] aligned