75. In Fig. 5.36, PQ ∥ RS, TR ∥ QU and ∠PTR = 42°. Find ∠QUR.
138°
Since PQ ∥ RS and TR ∥ QU, ∠PTR and ∠QUR are consecutive interior angles. Thus, ∠QUR = 180° − 42° = 138°.