we know that
area of the composite figure=area of the rectangle+area of semicircle
area of rectangle=b*h
b=10 ft
h=6 ft
area rectangle=10*6----> 60 ft²
area of semicircle=pi*r²/2
r=6/2----> 3 ft
area of semicircle=pi*3²/2-----> 14.13 ft²
area of the composite figure=[60+14.13]-----> 74.13 ft²-----> 74 ft²
the answer is
74 ft²