if the angles of an n sided polygon are in A.P and a>=20 and d>=20 then wat is the maximum possible value of n?	Choose the correct choice from the following answers: A) 12 B) 14 C) 21 D) 25 E) cant determine

Rationale: sum of interior angles of a polygon = ( n - 2 ) × 180 ° where n = number of sides there will be n angles which are in a . p . therefore , since we need to find maximum value of n , put minimum value for a and d . i . e . , take a = 20 and d = 20 then sum of the angles = n / 2 [ 2 × 20 + ( n − 1 ) 20 ] therefore , 10 n ( n + 1 ) = ( n − 2 ) 180 n = 14.52 since number of sides must be a positive integer , maximum value of n = 14 answer : b
Answer: B