Question 461265
Since this polygon has four angles it's a rectangle. We know that the sum of interior angles of the rectangle is 360 degree.We write the equation:

{{{(5x+30)+(10x-10)+(8x-1)+(6x-7)=360}}}, solving this equation we get:x=12.

Answer:The angles of the rectangle are:5*12+30=90; 10*12-10=110; 8*12-1=95 and
        6*12-7=65 degree.