∠R=∠T= 135° [Opposite Angles of a parallelogram are equal]
∠S+∠R=180° [They form a linear pair, because we know that the angles formed on the same side of a parallelogram are linear pair]
∠S+135°=180°
∠S=180°-135°
∠S= 45°
∠S=∠Q=45° [Opposite angles of a parallelogram are equal]
