Math CentralQuandaries & Queries


Question from SUDHIR, a teacher:

How can we find the all positive integral values for the third side of a triangle, whose other two sides measure 15 and 20 respectively.  (No other information viz. the type of triangle, area, perimeter or angles etc. is given.)

Hi Sudhir.

Any one side of a triangle must be shorter than the sum of the other two sides.

Therefore, the third side length x must be between 5 and 35, not including those endpoints:

5 < x < 35.

All whole numbers satisfying this range would form a triangle.


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