Maximal Area
Problem 681
Given positive integers , it may be possible to form quadrilaterals with edge lengths (in any order). When this is the case, let denote the maximal area of such a quadrilateral.
For example, , attained e.g. by a rectangle.
For example, , attained e.g. by a rectangle.
Let be the sum of over all choices for which is a positive integer not exceeding .
and .
and .
Find .