When inscribing a square in a circle, which of these should have equal lengths?

To show that polygon abcde is congruent to polygon fghij, a must be used to make the two polygons coincide. a sequence of two transformations that can be used to show that polygon abcde is congruent to polygon fghij is .

Compare the subtraction problems 6/8 - 5/8 = 1/8 and 6/9 - 7/9 = 1/9 why is the answer to the first problem positive and the answer to the second problem negative

Just tell me how to set up the equation.