Answer:
x=36°
- pentagon=540°
- one angle of the pentagon=108°
- the straight line =180°
- 180°-108°=72°
- 72° is for the angle of the triangle that consists x
- both of the angle is 72°
- the interior angle for triangle is 180°
- 180°-72°-72°=36°
hope it will be helpful. sorry if there is a mistake.