The correct option is C Area of irregular figure is greater by 3 sq.cm
As we can see the figure occupies,
9 complete squares, 6 more than half squares and 6 less-than half-squares
To get the area approximately, we can neglect the less than half squares and take more than-half squares as of full area
So area=(9×1)+(6×1)=15 sq. cms (approx.)
so it is greater than the rectangle by =15−12=3 sq. cms