Let D be a region bounded by a simple closed path C in the xy-plane. The coordinates of the centroid ( , ) of D are given below, where A is the area of D. = 1/2A x 2 dy = -1/2A y 2 dx Use the formulas to find the centroid of the triangle with vertices (0, 0), (a, 0), and (a, b), where a > 0 and b > 0. {x, y) = ( )