STUV is a parallelogram. SUW is a straight line. In a parallelogram, adjacent angles sum to 180&deg;.<br><br>From the figure, \(\angle STU = 135&deg;\) (given).<br>In parallelogram, \(\angle TUV = 180&deg; - 135&deg; = 45&deg;\).<br>Diagonal SU divides angle TUV. From the figure, \(\angle USV = 45&deg;\).<br><br>Final Answer: 45&deg;