This du today I NEED HELP

x = 8

Step-by-step explanation:

The perimeter of a body is the sum of all its sides.

  Perimeter of the triangle;

       hypothenuse + opposite + adjacent  = x+6 + x + 3 + x + 9 = 3x + 18

  Perimeter of the rectangle  = x+1 + x + 4 + x + 1 + x + 4 = 4x + 10

Now,

 Since their perimeter is equal;

                           3x + 18 = 4x + 10

                             3x - 4x  = 10 - 18

                               -x  = -8

                               x = 8