to find no. of sides

Asked by meghapte | 17th Jan, 2010, 03:35: PM

Expert Answer:

Sum of interior angles of a polygon = 180(n-2) ........where n is the number of sides.

The interior angles are in AP and smallest angle is 120 i.e. first term of AP.

Sum of interior angles =n(2a+(n-1)d)/2

180(n-2) = n(240+(n-1)5)/2

5n2-125n+720 = 0

n2-25n+144 = 0

The polygon can have 9 or 16 sides.






Answered by  | 17th Jan, 2010, 04:04: PM

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