Yes, Three Sisters is in four acts. This three-act thing is just another way of thinking about the structure.
The difference between 7 and 3 is 4.
the difference between a number and 3 is
The central of act 3 is a choce between
The difference between -1 and 3 is 4.
It is 5.8 minus 3 = 2.8
Zero. In general, the difference between any number and itself is zero.
A or the footing is at the base of the foundation. Usually but not always 3 times the width of the wall. This just make a base for the wall to sit on so that it doesn't push into the ground. Without it, the wall would act as a knife and with the weight of the structure, cut into the ground.
-1
The difference between -3 and 0 is 3 because your not taking anything away from negative 3 and your not adding anything to It either.
-15
3