SOLUTION: The angles of the quadrilateral are in A.P.The greatest angle of the quadrilateral is double the least. Find the angles of the quadrilateral.

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Question 1021365: The angles of the quadrilateral are in A.P.The greatest angle of the quadrilateral is double the least. Find the angles of the quadrilateral.
Answer by robertb(5830) About Me  (Show Source):
You can put this solution on YOUR website!
The sum of the first n terms of an AP is given by S%5Bn%5D=%28n%2F2%29%28a%5B1%5D%2Ba%5Bn%5D%29
==> S%5B4%5D+=+%284%2F2%29%28x%2B2x%29+=+2%283x%29+=+6x as per the given info.
But the sum of the interior angles of a quadrilateral is always 360 degrees.
Hence,
6x = 360
==> x = 60, and the angles of the quadrilateral are 60, 80, 100, and 120.