u see that 75 degree angle...that angle and the one next to it...the angle in ur triangle...they make a linear pair and are = to 180.....so the angle in ur triangle that has no number by it, is gonna be 180 - 75 = 105.
and the interior angles of a triangle = 180
< x + 105 + 32 = 180
< x + 137 = 180
< x = 180 - 137
< x = 43 <==