Draw a third parallel linea∘=35∘(Vertically opposite angles are the same) a∘=b∘=35∘ (Alternate angles are the same)140∘+d∘=180∘ (Sum of angles on a straight line is 180°)d∘=180∘−140∘d∘=40∘c∘=d∘=40∘ (Alternate angles are the same)b∘+c∘+x∘=360∘ (Sum of angles in a circle is 360°)35∘+40∘+x∘=360∘75∘+x∘=360∘x∘=360∘−75∘x∘=285∘