170.
18339-!-item-!-187;#058&011871 For any triangle T in the xy-coordinate plane, the center of T is defined to be the point whose x-coordinate is the average (arithmetic mean) of the x-coordinates of the vertices of T and whose y-coordinate is the average of the y-coordinates of the vertices of T. If a certain triangle has vertices at the points (0,0) and (6,0) and center at the point (3,2), what are the coordinates of the remaining vertex?
(A) (3,4) (B) (3,6) (C) (4,9) (D) (6,4) (E) (9,6)
请教各位NN，这道题到底在说什么？好像能在一个圆上求解。搞了半天也搞不懂。请指教。 | 
