2(3) - 3 + 7 = 6 - 3 + 7 = 10
Check the picture below.
so the lunchbox is really a semi-circle with a radius of 3, sitting on top of a square of 6x6, with a lenght of 10.
the volume of the lunchbox then will be the area of the semi-circle and square times the length.
I assume it is the last one