Notice that since the bottom side of the figure has a length of 10cm while the part that corresponds to the rectangle is only 6cm long, then the base of the triangle is 4cm long. The height of the triangle is 4cm long, since it is the same as the height of the rectangle. Additionally, the diameter of the semicircle turns out to be equal to 4cm, then its radius (which is half the diameter) must be 2cm long.
Use these data to find the area of each figure:
Semicircle
The area of a semicircle is half the area of a circle:
Rectangle
Triangle
Total area:
Therefore, the total area of the figure is: