Each interior angle of a regular pentagon is ${108}^{\circ }$, so $\angle \mathrm{SRQ}={108}^{\circ }$. As SR=QR, the triangle is isosceles with $\angle \mathrm{RQS}=\angle \mathrm{RSQ}=\angle 36$. Similarly, $\angle \mathrm{SRT}=\angle \mathrm{STR}={36}^{\circ }$. So $\angle \mathrm{SUR}=(180-2\times 36{)}^{\circ }={108}^{\circ }$. From the symmetry of the figure, $\angle \mathrm{PUR}=\angle \mathrm{PUS}=({360}^{\circ }-{108}^{\circ })/2={126}^{\circ }$.