Respuesta :

Since m is a straight line
Angle 5 + Angle 6 = 180°
=> Angle 5 + 75° = 180°
=> Angle 5 = 180° - 75°
=> Angle 5 = 105°

But, Since line l parallel to line m,
Angle 5 = Angle 1 [corresponding angles]
Hence, Angle 1 = 105°