Python 3   ||   2 lines,  geometry      ||   T/S: 99% / 93%
\n\nclass Solution:\n    def areaOfMaxDiagonal(self, dimensions: List[List[int]]) -> int:\n\n        a,b = max(dimensions, \n                key = lambda x: (x[
\n```\nclass Solution:\n    def areaOfMaxDiagonal(self, dimensions: List[List[int]]) -> int:\n\n        a,b = max(dimensions, \n                key = lambda x: (x[0]*x[0]+x[1]*x[1], (x[0]*x[1])))\n\n        return a*b\n```\n[https://leetcode.com/problems/maximum-area-of-longest-diagonal-rectangle/submissions/1139186165/](http://)\n\n\nI could be wrong, but I think that time complexity is *O*(*N*) and space complexity is *O*(1), in which *N* ~ `len(dimensions)`.
['Python3']