area of circle = pi r squared
diameter is 63cm
then radius is 63/2, or 31.5cm
3.14*31.5^2= 3115.665cm squared
3115.665 is the area of the whole circle, divide that by two to get the area of the semicircle
so 3115.665/2 = 1557.8325 cm squared
1557.8325 rounded to two decimal points is 1557.83cm squared
1557.83cm squared is the area of the semi circle
hope that helped! :)