Et d be a region bounded by a simple closed path c in the xy-plane. the coordinates of the centroid x, y of d are given below, where a is the area of d. x = 1 2a c x2 dy y = − 1 2a c y2 dx use the formulas to find the centroid of the triangle with vertices (0, 0), (a, 0), and (a, b), wh