hi
reminder :
area of square : side * side
area of circle : π * radius²
here : side of square is 30 meters
so area of square : 30*30 = 900 m²
One side of the square is a diameter of the circle : a diameter is twice the radius.
so diameter = 30 so radius = 30/2 = 15
now if radius is 15 so area of circle : π*15² = 706.5 m²
so area of the figure is : 900 + 706.5 = 1 606.5 m²
..