Solution: As can be seen from the figure, the radius of the semicircle is 8/2=4cm, that is, the height of the trapezoid is 4cm.

Trapezoidal area: (10+8)*4* 1/2=36.

Area of semicircle: 3. 14*4? * 1/2=25. 12

Shadow area: 36-25. 12= 10.88