A preimage and its image are 112 degrees apart. If the preimage was reflected over two intersecting lines, at what angle did they intersect?

There is diarrhea on the floor. what do i do? my mum gonna see that i diarrhea on the floor! * don't report, i'm serious! *

65 8 7 4 5 6 8 4 3 2 1 9 5 6 4 2 1 6 5 1 5 1 3 2 3 5 multiply the third number in the first row by the seventh number in the third row. add this result to the fifth number in the second row. add to this total ten times the fourth number in the third row. subtract the eighth number in the first row from the result.

Which geometric principle is used to justify the construction below?