Miklos Schweitzer 1969_10
Source:
October 15, 2008
real analysisanalytic geometryreal analysis unsolved
Problem Statement
In -dimensional Euclidean space, the square of the two-dimensional Lebesgue measure of a bounded, closed, (two-dimensional) planar set is equal to the sum of the squares of the measures of the orthogonal projections of the given set on the -coordinate hyperplanes.
L. Tamassy