Solve for x, x= blank degrees. may you also tell me how so i can understand it?
4 sided polygon, not a square
the given degrees are 121, 108, 102, and 100

We have to arrange different numbers ranging from 1 to 12 in each boxes such that the sum along each of the side is equal to 26.

In the first row we arrange the numbers as:

  8   9   3   6

( since, 8+9+3+6=26)

In the last row we write the numbers as:

  5    10   4   7

( since, 5+10+4+7=26)

In the first column we arrange numbers as:

   8

    1

   12

    5

( Since, 8+1+12+5=26 )

In the last column we arrange numbers as:

    6

    11

    2

    7

( Since, 6+11+2+7=26)