G is the centroid of triangle ABC, prove that AB^2+BC^2+CA^2=3(AG^2+BG^2+CG^2)

Answer 1

this should point out the solution.

google is your friend -- use it.

https://math.stackexchange.com/questions/460588/compare-the-sum-of-the-squares-of-the-median-of-a-triangle-to-the-sum-of-the-squ

Answer 2

give answer