angle U and angle I are suppose to go together
Given that the octagon rotates 360 degrees, it is a given that for every regular division of the polygon (360/8 = 45 degrees), the image would coincide with the pre-image during the rotation. Therefore, the octagon would coincide a total of 8 times as it rotates 360 degrees about its center.
I don't know what the "six-step method" is, but I do know how to solve the problem:
Let x = number of gallons of 50% solution
amount of antifreeze in 50% solution = 0.50x
amount of antifreeze in 10% solution = 0.10(80) = 8
amount of 40% solution = 0.40(x+80) = 0.40x + 32
Then, 0.50x + 8 = 0.40x + 32
0.10x = 24
x = 240 gal
