The composite section is divided into three simple figures, a triangle, a rectangle and a semicircle
Now, area of triangle A1 = 1/2 × 3 × 4 = 6 m2
Area of rectangle A2 = 6 × 4 = 24 m2
Area of semicircle A3 = 1/2 × π × 22 = 6.2832 m2
∴ Total area A = 36.2832 m2
The coordinates of centroids of these three simple figures are: