the centroid of a triangle whose two vertices are (1,5,-2) and (3,2,7) is (-1,2,3) find the coordinates of third vertices . Also find the centroid of triangle formed by joining the mid point of given triangle sides Share with your friends Share 1 Nihma answered this (1+3+x)÷3= -1 (4+x)= -1*3 x= -3-4 x= -7. similarly find y & z coordinates -5 View Full Answer