Sunday 30 June 2013

The difference between any two consecutive interior angles of a polygon is 5°. If the smallest angle is 120°, find the number of the sides of the polygon.

The difference between any two consecutive interior angles of a polygon is 5°. If the smallest angle is 120°, find the number of the sides of the polygon.

Answer

The angles of the polygon will form an A.P. with common difference d as 5° and first term a as 120°.
It is known that the sum of all angles of a polygon with n sides is 180°

2 comments:

  1. The Ncert book has the ans as 9 only.
    How/why have they ruled out 16

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  2. If n = 16, then the sixteenth angle, by putting in the formula [an = 120 + (n-1)*d], will be 195 which is not possible for a polygon.

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