The harmonic mean of 2 numbers a and b is defined to be the reciprocal of the average (arithmetic mean) of these numbers' reciprocals.
In essence, the harmonic mean of a and b = = .
Prove that the segment drawn through the point of intersectionof both diagonalsof an isosceles trapezoidthat is parallel to both bases is equal to the harmonic meanof the bases of this isosceles trapezoid.
Can you prove this is true for ANY TRAPEZOID (and not just an isosceles trapezoid?)