The shape consists of half a circle on top of a trapezium.
The dimensions of the trapezium are given:
Base 1 = 9 m
Base 2 = 23 m
Height = 7 m
The radius of the circle is half the diameter:
r = 9/2 = 4.5 m
Now compute the area of the trapezium:

Substituting:

The area of the semicircle is:

Substituting:

Calculating:
Ac=31.8 square m
The total area of the shaded figure is:
At = 112 + 31.8 = 143.8 square m