Respuesta :

Sum of all the interior angles = (5-2)x180 = 540°
540 - 100 - 120 - 100 - 90 = 130°
So the last unknown angle in the polygon is 130°

Sum of all the adjacent  angles on a straight line is 180°
Angle 1 = 180 - 130 = 50°
Q&A Education