180 -55 = 125 angle to the left of 55 deg
125 + 25 + 150 angles we know inside leftmost triangle
180 - 150 = 30 solve for third angle angle inside a triangle always sum to 180 deg
30 + 90 = 120 angles we know in the triangle including x angle
180 - 120 = 60 solve for x
60 =x