\[\begin{align}  & \angle WYX=180{}^\circ -\angle XYZ \\ & \{\text{Sum of }\angle s\text{ on a straight line }\!\!\}\!\!\text{ } \\ & \angle WYX=180{}^\circ -117{}^\circ =63{}^\circ  \\ & \angle WOX=2\angle WYX \\ & \{\angle \text{ at centre}=2\times \angle \text{ at circumference }\!\!\}\!\!\text{ } \\ & t=2(63{}^\circ )=126{}^\circ  \\\end{align}\]