The given composite figure can be divided into two rectangles:
A1 = 150 × 12 = 1800 mm2
A2 = (200 – 12) × 12 = 2256 mm2
Total area A = A1 + A2 = 4056 mm2
Selecting the reference axis x and y as shown in Fig. The centroid of A1 is g1 (75, 6) and that of A2 is:
Thus, the centroid is at \(\bar x\) = 36.62 mm and \(\bar y\) = 61.62 mm as shown in the figure.