It took 12 days for all the 60 gallons of water to leak out of the barrel. If you divide 60 by 5 you will get 12.
Check the picture below.
recall that in a square, all sides are equal, so if we make b = a, then we get that for one side, also recall that the area of a rectangle is length*width, so in this case,
<4 and <2 corresponding angles
<6 and <3 alternate interior angles
<4 and <5 alternate exterior angles
<6 and <7 interior angles on the same side of transversal